How to Grill Flank Steak: High Heat, Slicing, and Marinade

To grill flank steak, marinate for 2 to 6 hours, then cook over direct high heat at 450 to 500°F for 4 to 5 minutes per side until the center reads 125 to 127°F before resting. Let it rest 5 to 8 minutes, then slice thin against the grain — that step is not optional, it is the difference between tender and chewy.

What makes flank steak different from other grilling cuts

Flank steak is cut from the abdominal muscles of the cow — a high-activity muscle group that develops long, tightly wound fibers with minimal intramuscular fat. Compared to a ribeye or New York strip, flank is considerably leaner, averaging around 8 grams of fat per 4-ounce serving versus 17 grams in a ribeye. It is also much thinner, typically 3/4 to 1 inch at the thickest point and 1.5 to 2.5 pounds per cut.

That lean, flat structure means flank steak behaves differently on the grill than premium steakhouse cuts. Three rules apply here that do not apply to ribeye:

High heat only. Flank steak cooks in 8 to 10 minutes total at 450 to 500°F. There is no reason to use indirect heat for a whole flank — it is thin enough to grill entirely over direct heat without developing a wide overcooked band.

Doneness matters more than with fattier cuts. A ribeye at medium-well is still edible because its fat carries moisture and flavor through high temperature. A flank steak cooked to medium-well (150°F and above) becomes noticeably dry and stringy. Medium-rare (130 to 135°F) is the target. Medium (135 to 145°F) is acceptable. Above that, the cut is better served thin-sliced for fajitas or tacos where sauce and toppings compensate for the dryness.

Slicing against the grain is mandatory. Flank steak has strongly directional grain running along the length of the cut. Slice with the grain and you cut along the long muscle fibers, leaving unbroken strands that require significant chewing. Slice against the grain — perpendicular to the fibers — and each fiber is cut into very short segments, producing a result that is genuinely tender from the same piece of meat.

Should you marinate flank steak?

Yes, for almost every preparation. Flank steak is lean, which means it lacks the fat reserves that keep fattier cuts moist through high-heat cooking. A marinade solves this in three ways: the acid in the marinade (citrus, soy sauce, vinegar) partially breaks down surface proteins and tenderizes the muscle fibers; the oil carries fat-soluble flavor compounds into the meat; and the salt seasons the interior, not just the surface.

A marinade for flank steak needs four components: acid, fat, aromatics, and salt. The acid does the tenderizing work. The oil carries flavor. Aromatics (garlic, ginger, cumin, smoked paprika, chili) add complexity. Salt seasons deeply.

A simple high-performance marinade:

• 3 tablespoons olive oil
• 3 tablespoons soy sauce (provides both salt and mild acid)
• 2 tablespoons fresh lime juice
• 4 garlic cloves, minced
• 1 teaspoon smoked paprika
• 1 teaspoon ground cumin
• 1/2 teaspoon black pepper

Combine everything in a large zip-lock bag with the flank steak. Squeeze out excess air and seal. Refrigerate for at least 2 hours and up to 6 hours. Avoid marinating longer than 6 to 8 hours in a strongly acidic marinade — the exterior proteins over-break down and the surface develops a slightly mushy texture when grilled.

If you prefer a dry-brine approach, pat the steak completely dry, apply 3/4 teaspoon of kosher salt per pound plus coarse black pepper, and refrigerate uncovered on a wire rack for at least 1 hour (up to 24 hours). This seasons deeply without acid tenderizing, and leaves the surface very dry for excellent crust formation.

How to prep flank steak for the grill

Remove from the refrigerator 20 to 30 minutes before grilling. Cold meat hitting a 500°F grate takes longer to reach final temperature, which means more time at high heat and a higher risk of overcooking the exterior while the interior catches up. Bringing the steak closer to room temperature shortens that gap.

Pat completely dry before placing on the grill. Whether you marinated or dry-brined, remove as much surface moisture as possible with paper towels. Surface moisture converts to steam on contact with the hot grate, lowering the grate temperature momentarily and delaying the Maillard browning reaction that creates the crust. A dry surface browns faster and more evenly.

Score the surface lightly (optional). Some cooks make shallow diagonal cuts, about 1/4 inch deep, across the surface in a diamond pattern. This increases surface area for browning and lets the marinade penetrate further during refrigeration. It is not required, but for a fajita-style preparation where you want maximum crust and marinade flavor, light scoring helps.

How to grill flank steak: step-by-step

Step 1: Preheat the grill to high. For a gas grill: light all burners to high and close the lid for 10 to 15 minutes until the grate temperature reaches at least 450°F, ideally 500°F. For a charcoal grill: light a full chimney of briquettes or lump charcoal and wait until the coals are fully ashed over — about 20 minutes. Pour the coals in an even layer directly below the cooking grate. A full chimney over a 22-inch kettle produces direct-heat temperatures above 500°F at the grate. View charcoal chimney starters on Amazon

Step 2: Oil the grates. Fold a paper towel into a pad, soak it in vegetable oil, and grip it with long-handle tongs. Wipe the preheated grates thoroughly right before placing the steak. Oiled grates prevent the steak from bonding to the metal, which tears the crust when you try to flip. View long-handle grill tongs on Amazon

Step 3: Place the steak directly over the heat. Lay the flank steak flat on the direct zone. The entire cut should be over active heat — flank steak is not a candidate for the indirect zone. Close the lid immediately to maintain grate temperature.

Step 4: Cook 4 to 5 minutes on the first side without moving. Resist lifting the steak to check progress. Flank steak develops its crust from sustained contact with the hot grate. Moving it interrupts that contact and produces an uneven, patchy crust. After 4 minutes, lift one edge with tongs and look for deep brown color. If it looks pale or grey, wait another 60 seconds before flipping.

Step 5: Flip once and cook the second side. Flip the steak using tongs — not a fork. Piercing the meat releases juices onto the hot grate, drying the interior. Cook the second side for 3 to 4 minutes. The steak has already risen significantly in internal temperature from the first-side cook, so the second side finishes faster.

Step 6: Pull at temperature, not by time. Start checking internal temperature at the 3-minute mark on the second side. Insert an instant-read thermometer into the thickest part of the steak at a horizontal angle from the side — not straight down through the top. Target 125 to 127°F for medium-rare (carryover will raise it to 130 to 135°F during the rest), or 135 to 137°F for medium (will rest to 140 to 145°F). View the ThermoWorks Thermapen One on Amazon

Step 7: Rest 5 to 8 minutes before slicing. Move the steak to a cutting board and rest uncovered for 5 to 8 minutes. During this time, the fibers relax and reabsorb the juices driven to the center by heat. Skip the rest and those juices pour onto the cutting board instead of staying in the meat. Flank steak is thin enough that 5 minutes is sufficient — it will not cool to an unacceptable eating temperature during this window.

Target temperature guide

Medium-rare is the recommended target for grilled flank steak. The muscle fibers are lean and tight — the less time spent at high internal temperatures, the more moisture stays in the meat. Above medium-well, the cut becomes noticeably stringy and better suited for applications where sauce or accompaniments compensate.

The 5 to 8°F of carryover heat that happens during the rest is significant for a cut this thin — account for it by pulling slightly earlier than your final target temperature.

How to slice flank steak against the grain

Slicing against the grain is the defining technique for flank steak. Done correctly, it produces a result that is noticeably tender. Done incorrectly — with the grain — it leaves long, unbroken muscle fibers that require significant chewing regardless of how well the steak was cooked.

How to identify the grain direction. Look at the surface of the rested steak. You will see clearly visible parallel lines running along the length of the cut — these are the edges of the long muscle fibers. In most flank steaks, the grain runs lengthwise along the cut from one end to the other.

How to slice against the grain. Position the steak on the cutting board so the grain runs left to right. Now slice straight down — or at a 45-degree angle for wider presentation slices. Each cut is perpendicular to the grain, which means each slice contains only very short fiber segments rather than long, unbroken ones.

Slice thin. Flank steak sliced at 1/4 inch thickness eats dramatically better than slices cut at 1/2 inch. Even when slicing against the grain, thick slices present more fiber stacked together and require more effort to cut through. At 1/4 inch, each slice nearly melts in the mouth. Use a sharp knife and long, confident strokes rather than a sawing motion.

The bias cut. Holding the knife at a 45-degree angle to the cutting board (angling the blade away from vertical while still cutting against the grain) increases the surface area of each slice, making each piece appear wider and thinner. This is standard restaurant presentation for flank steak and slightly improves texture.

Flank steak vs skirt steak on the grill

Both cuts are lean, flat, heavily grained, and benefit from marinating and slicing against the grain. The differences affect how you manage them on the grill.

Flank steak is thicker and cooks more forgivingly than skirt, making it the better starting point for home grillers who want predictability. Skirt steak has a more pronounced beef flavor and is the traditional choice for Tex-Mex fajitas — but at 2 to 3 minutes per side, the window between underdone and overdone is narrow. If you are new to these cuts, start with flank.

Common mistakes that ruin grilled flank steak

Slicing with the grain. The single most common mistake and the one with the most dramatic negative impact. Even a perfectly cooked, medium-rare flank steak becomes tough and difficult to eat when sliced along the fibers. Before the first cut, look at the grain direction and rotate the board so you are slicing across it.

Cooking past medium. Unlike ribeye, flank steak has no fat reserves to keep it moist at higher temperatures. At 155°F and above, the steak becomes dry and stringy. The cut is best appreciated at medium-rare. If your household prefers well-done beef, choose a fattier cut.

Skipping the marinade without a proper dry-brine. A 10-minute salt-and-pepper application before grilling produces a surface-seasoned but tough result. Either marinate for 2 to 6 hours, or dry-brine with kosher salt for at least 1 hour uncovered in the refrigerator.

Grilling a wet surface. Pulling the steak directly from the marinade bag and placing it on the grate without patting dry causes the wet surface to steam rather than sear, delaying browning and adding grill time. Always pat dry regardless of marinade.

Using indirect heat on the whole steak. Flank steak is thin enough to cook entirely over direct heat. An indirect finishing phase is unnecessary and adds time without benefit, increasing the risk of overshooting your target temperature.

FAQ

Bottom line

Flank steak is one of the most rewarding cuts for the backyard grill: 1.5 to 2 pounds of lean, intensely flavored beef that cooks in under 15 minutes total and feeds 3 to 4 people. Marinate for 2 to 6 hours, grill over direct high heat at 450 to 500°F for 4 to 5 minutes per side, pull at 125°F, rest 5 to 8 minutes, and slice thin against the grain. Every step matters, but the slicing direction is the one technique that converts an average result into a genuinely impressive one — and it costs nothing to do correctly.

For related reading: how to grill a perfect steak — ribeye, strip, and doneness, how to grill tri-tip, direct vs indirect grilling explained, and best instant-read thermometers for grilling.