The study examines whether there are socioeconomic differences between young adult car drivers involved in road-traffic crashes with regard to crash-injury severity and crash circumstances. Differences in social patterning based on socioeconomic position (SEP) of origin and of destination, and also the effect of gender, are considered. Subjects born in 1970-1972 were extracted from the Swedish Population and Housing Census of 1985 (n = 329,716). Individual records from the 1985 census were linked to road-traffic data for the period 1988-2000 on the basis of a search for each subject's first police-registered road-traffic crash as a car driver (n = 12,502). Information on household socioeconomic group was taken from the census of 1985, and data on completed education at age 28-30 were gathered from Sweden's Register of Education. Two categories of crash severity were analysed (minor/no injury and severe/fatal injury), and also five crash circumstances (based on a classification of five crash descriptors). Both crash severity and crash circumstances are unequally distributed across social groups among young adult drivers. Social patterning is more pronounced for severe injuries/fatalities, and is consistently so across crash circumstances depending on SEP of destination, particularly for males. Socioeconomic differences are more pronounced for crash circumstances characterised as front-on and overtaking collisions and for single-vehicle crashes (43% of total crashes). In conclusion,the excess risk of young drivers from lower socioeconomic groups is consistent over crash severity but more pronounced as severity increases and for certain crash circumstances.