This report presents:
- on the one hand, a survey of national data on moped accidents which shows that it is a major problem in France,
- on the other hand, the results of a multipurpose investigation during 1976 in the Hauts de Seine Department which consisted in analysing obstacles collided with collision configurations and moped rider kinematics.
Frequency, severeness and location of injuries are studied as a function of their causes. The site of cranial-facial impact is given as well as the reasons of the low effectiveness of moped rider helmets at the present time in France.