The aim of the study was to compare the clinical features and predisposing characteristics of patients with an early onset of bulimia nervosa with those with a more typical onset. Twenty-three cases of early onset bulimia nervosa (onset age 15 or below) were compared with 23 sex- and class-matched cases of typical onset (onset age 17 to 21) using a retrospective case-control design. No difference was found in eating symptomatology between the two groups. Deliberate self-harm was more frequent in the early onset group, and there was a trend towards more depression among their relatives. Inadequate parental control occurred more often in the early onset group, but other indicators of intrafamilial disturbance did not differ in the two groups. There was also a trend for the early onset group to be exposed to more cultural stress as a result of family migration. Early onset patients were found to have a higher loading on risk factors than typical onset patients.