Four family practice resident physicians provided a school-based educational intervention designed to increase the use of bicycle helmets by elementary school children in three of six public schools and to produce more favorable parental attitudes toward bicycle helmets. The effect of the one-week intervention was assessed by two parent surveys and direct observation of children riding bicycles to school. Results indicate that 60 helmets were purchased. Parents reported a change in barriers to helmet purchase, an increase in helmet ownership (13% to 27%), but observed helmet use did not increase. Both helmet ownership and use were reported to be more frequent among families with higher income and educational levels.