Diablo's Southwest Grill in Charleston: Mesquite-Grilled Tex-Mex on King Street

What to expect at Diablo's Southwest Grill

Diablo's Southwest Grill sits on King Street in downtown Charleston and serves Tex-Mex built around a mesquite grill. The restaurant focuses on grilled proteins—fajitas, carne asada, grilled fish—paired with house-made salsas and traditional sides like black beans and cilantro rice. The space is casual and loud, with a bar that runs the length of the dining room and a patio that opens to the street. You order at the counter and find a seat; service is quick and the kitchen moves fast even during lunch rush.

The menu is straightforward: fajitas come in chicken, beef, shrimp, or vegetarian versions; tacos are served on corn or flour tortillas; enchiladas and burritos round out the entrées. Most dishes run between $12 and $18. Margaritas are the signature drink, made with fresh lime juice and available frozen or on the rocks. The restaurant does not take reservations, so expect a wait on weekends or during peak dinner hours—typically 6 to 8 p.m.

Key Takeaways

• Diablo's specializes in mesquite-grilled fajitas and carne asada, with proteins cooked to order in front of an open flame.
• The restaurant operates counter-service only, with no reservations, so arrive early or expect a 20- to 40-minute wait on busy evenings.
• House-made salsas and fresh lime margaritas are worth ordering, and the patio is a good spot to wait for a table with a drink in hand.
• Prices are moderate for downtown Charleston, with most entrées under $20 and lunch specials available weekdays from 11 a.m. to 3 p.m.

The mesquite grill and what it changes

The mesquite grill is the engine of the kitchen. Fajitas arrive sizzling on a cast-iron plate, the meat charred at the edges and still pink in the center. Carne asada—thin-sliced grilled beef—has a smoky crust that you taste before the meat itself. Grilled fish tacos come with a char that adds depth to mild white fish. This is not the same as Tex-Mex made on a flat-top griddle; the open flame creates a texture and flavor that matters.

The grill also means timing is visible. You watch your fajitas cook if you sit at the counter, and you can ask for meat cooked a specific way—well-done, medium, rare—without the kitchen treating it as unusual. Vegetarian fajitas use grilled peppers, onions, and mushrooms, and they get the same char treatment as the meat.

Salsas and sides that anchor the meal

Diablo's makes its salsas in-house daily. The red salsa is tomato-forward with a medium heat; the verde uses tomatillos and jalapeños and is brighter and spicier. Both come with warm tortilla chips at the start of the meal. A third salsa—sometimes pico de gallo, sometimes a corn salsa—rotates seasonally. The salsas are the reason to order extra chips, and they are also why the tacos and enchiladas taste better here than at chains.

Black beans come refried and creamy. Cilantro rice is cooked with lime and garlic. Grilled corn with cotija cheese and chili powder is available as a side. These are not afterthoughts; they are cooked with the same attention as the proteins.

Fajitas and how to order them

Fajitas are the best reason to come. They arrive on a sizzling plate with grilled peppers and onions, warm tortillas on the side, and a small bowl of sour cream. You build your own tacos, which means you control how much filling goes in each one and whether you use corn or flour tortillas. Chicken fajitas are tender and absorb the char from the grill. Beef fajitas use a cut that stays juicy even when cooked through. Shrimp fajitas cook quickly and have a slight char on the outside while staying tender inside.

The vegetarian version is not a side dish masquerading as an entrée. Grilled mushrooms, peppers, and onions have their own texture and flavor, and the plate is filling. Fajitas for two are available and come with double the protein and vegetables; they are a good choice if you want to try two proteins or if you are genuinely hungry.

Margaritas and the bar

The margaritas are made with fresh lime juice, tequila, and Cointreau, and they are available frozen or on the rocks. A standard margarita costs around $9 to $11. The frozen version is smooth and cold; the on-the-rocks version lets you taste the tequila more clearly. The bar also serves Mexican beer—Corona, Modelo, Pacifico—and a short list of tequilas if you want to order a shot or a neat pour.

The bar is a good place to wait for a table. You can order a drink and an appetizer—queso fundido, guacamole, or nachos—and eat while you wait. The bartenders work fast and the noise level is high, so it feels less like waiting and more like being part of the scene.

When to go and what to know before you arrive

Lunch is quieter than dinner. Weekday lunch from 11 a.m. to 3 p.m. includes specials—a fajita plate with a drink for a set price, or a taco plate with rice and beans. You can usually walk in and get a table without waiting. Dinner service starts at 5 p.m., and the restaurant fills up by 6:30 p.m. Friday and Saturday nights are the busiest; expect a 30- to 45-minute wait if you arrive between 7 and 8 p.m.

The restaurant does not take phone reservations or hold tables. You put your name on a list at the counter and wait in the dining room or at the bar. The patio is first-come, first-served and fills up quickly on warm evenings. Parking on King Street is metered; there is a parking garage two blocks away on Wentworth Street. The restaurant is cash and card; there is no minimum for card payments.

Frequently Asked Questions

Do they have vegetarian options beyond fajitas?

Yes. Vegetarian enchiladas, burritos, and tacos are on the menu. The enchiladas come with cheese and are topped with salsa and sour cream. Vegetarian burritos can be filled with beans, rice, cheese, and peppers. All use the same house-made salsas and sides as the meat dishes.

Can I order fajitas for one person?

Yes. Single fajita plates come with one protein, grilled vegetables, tortillas, and sides. They are the same price as any other entrée. Fajitas for two are available if you want more food or want to try two proteins in one meal.

Is the patio heated in winter?

The patio has overhead heaters, so it is usable on cool evenings. On very cold nights it may still be uncomfortable. Call ahead if you want to know whether heaters will be on during your visit.

What time does the kitchen close?

The restaurant closes at 10 p.m. most nights, though hours may vary seasonally. The kitchen stops taking orders 15 to 20 minutes before closing time. Arriving close to closing means a shorter wait but a rushed meal.

Do they make their own tortillas?

No. Tortillas are sourced from a supplier, but they are warmed on the grill before service. The house-made salsas and the quality of the proteins are where the kitchen focuses its effort.