Soak wooden skewers in water for 30 minutes. Mix the parsley, olive oil, lemon juice and garlic in a small bowl. Thread the tomatoes, onion, bell pepper and shrimp alternately on the wooden skewers and sprinkle with salt and pepper. Brush with the olive oil mixture and arrange on a platter. Chill, covered, for up to 2 hours.
Preheat the grill. Arrange the skewers on the grill rack and grill for 2 minutes per side or until the shrimp turn pink and are no longer translucent, turning occasionally.