The purpose of this qualitative study is to investigate young people's perceptions, in Barcelona, Spain, about the evolution, magnitude, causes and determinants of traffic crashes, to describe their opinions on road safety regulations, and to explore their suggestions and proposals. Interviews were conducted with 43 key informants and 12 focus groups involving 98 participants. Discussion guides were designed to get insight on perceptions of relevance and trends in road traffic injuries, determinants of these, regulations and enforcement, as well as to gather their own ideas for reducing traffic injuries. Young people are aware that traffic injuries are a relevant and increasingly serious problem. The main determinants identified are: driving under the influence of drugs and alcohol, fatigue, night driving, unsafe infrastructures, age of drivers and lack of public transport alternatives. Young people admit that fines, speed cameras and alcohol breath testing reduce risky driving. They prefer community work to fines. They have a poor image of public administrations in charge of prevention of traffic injuries. They demand information on traffic regulations and politicians' decisions, and a considerable increase in weekend and night time public transport. Effectiveness of interventions to reduce traffic injuries can be improved by taking the recipients' perceptions into account.