Whisk together the chipotle chili powder, brown sugar, cumin, season salt and pepper in a small bowl.
Place the shrimp in a large bowl, toss with olive oil and garlic. Add the spice rub and stir well to coat; set aside.
Heat grill to high.
Skewer shrimp with 2 skewers to prevent difficulty in turning shrimp.
Place on a grill to cook until just cooked through, 2 to 3 minutes per side.