We identified children ages 0 to 14 years injured in traffic as pedestrians or bicyclists in Montreal, Canada. Two hundred children with injuries who received a score of 2 or more on the Maximum Abbreviated Injury Severity scale were considered as cases and compared with 400 uninjured children seen in the same hospitals for non-traumatic reasons. Systematic, blinded interviews and tests were conducted with parents to determine the role of a series of social, familial, personal, and behavioral characteristics. After adjustment for age, gender and socioeconomic area of residence, logistic regression analyses showed higher risks of injury to be related to fewer years of parents' education, a history of accident to a family member, an environment judged as unsafe, and poor parental supervision. Absence of physical health problems, fewer family preventive behaviors and reported lack of cautiousness were also related to a higher risk, whereas neither aggressivity nor behavioral disturbance, whether internalizing or externalizing, showed any such relation. These data suggest that the child's personality and behavior are weaker risk factors for pedestrian and bicyclist injuries than are family and neighborhood characteristics.