In Italy, motor-vehicle crashes are the leading cause of death among persons aged 15-20 years, and motorcycles account for a substantial proportion of traffic-related fatalities: in 1993, of the 6349 traffic-related deaths reported in Italy, 1342 (21.1%) occurred among motorcycle and moped users, and 261 (19.4%) of these deaths were among persons aged 15-20 years. Because of the risks for head injury and death, in 1986 a national law was enacted requiring operators of motorcycles or mopeds to use helmets under specified conditions. To asses compliance with this law and factors associated with helmet use among adolescents in a metropolitan area, in October 1994 the National Institute for Health conducted a survey of a sample of high school students in Rome. This report presents findings of this survey, which indicate that helmet use was low, particularly among moped users and among passengers.