Objective. To assess the possibility of preventing consequences of bicycle accidents. Design. Retrospective study. Setting. The Netherlands. Material and method. The data on mortality and hospital admissions of children aged 0-14 years were analysed. The data on traffic accident fatalities were obtained from the Traffic Accidents Registration (for 1991) and those on admissions from the Dutch Centre for Health Care Information (for 1990). Results. In 1991, 82 children (1-14 years) died from the consequences of a traffic accident. Most died after a bicycle accident. The number of hospital admissions because of traffic accidents in the age group 0-14 years in 1990 amounted to 2839, of which 46% were due to a bicycle accident. Most of the children aged 0-14 years admitted because of bicycle accidents had head and skull injuries. In 69% of the bicycle accidents no motor vehicle was involved. Conclusion. Because of the high frequency of head injuries, wearing a bicycle helmet should be promoted strongly, legal obligation giving the fastest and best results. Several prevention strategies are discussed.