We interviewed 516 bicyclists over age 10 regarding helmet use and head injuries. Although 19 per cent owned helmets, only 8 per cent were wearing them when interviewed. Riders wearing helmets were more highly educated and reported higher car seat belt use. Nearly 4 per cent of the bicyclists reported striking their heads in a cycling mishap during the previous 18 months; those wearing helmets at the time of the mishap were less likely to have sustained head injuries.