Excessively optimistic judgements of driving competency and accident risk have often been implicated in the disproportionate involvement of young males in traffic crashes. In this study, young male and female drivers (ages 18-24) were asked to judge their relative driving safety, skill, and accident likelihood. Comparisons were made using both peers and the average motorist as referent groups. Subjects then rated 15 risky driving behaviors on four dimensions: frequency in everyday driving, seriousness, accident potential, and apprehension likelihood. Self-report driving experience/history data were also collected. Substantial optimism was evident in both sexes, but males tended to be more optimistic, particularly when judging their driving skill. Males were equally optimistic with respect to the two referent groups; females tended to be less optimistic when making comparisons to the average motorist. Males and females held similar perceptions concerning the frequency and accident likelihood of the risky behaviors, but males perceived the behaviors as generally less serious and less likely to results in accidents. Regression analyses showed that considerably more variance in optimism could be explained for males than females. Driving record was the single best predictor of perceived safety; its role, however, was diminished for perceived skill and subjectively estimated accident likelihood.