Gather all ingredients.

Preheat an outdoor grill for medium, indirect heat and lightly oil the grate.

Season pork tenderloins with garlic powder, salt, and pepper. Place 1/2 of the BBQ sauce into a small bowl for basting; set aside remaining BBQ sauce for serving.

Cook pork on the preheated grill over indirect heat for 30 minutes.

Brush pork with BBQ sauce, turn, and brush again, using all sauce in the small bowl. Continue cooking until an instant-read thermometer inserted into the center reads 145 degrees F (63 degrees C), about 15 more minutes. Let pork rest for 10 minutes.

Slice pork and serve with reserved BBQ sauce.