1In shallow glass or plastic dish or resealable food-storage plastic bag, mix oil, lemon juice, garlic, rosemary, salt and pepper. Add chicken, turning to coat with marinade. Cover dish or seal bag; refrigerate 30 minutes to marinate.
2Heat gas or charcoal grill. Remove chicken from marinade; discard marinade. Place chicken on grill over medium heat. Cover grill; cook 12 to 15 minutes, turning once, until juice of chicken is clear when center of thickest part is cut (at least 165°F).