This study examines the impact of pregnancy on the reported eating behaviour of 20 untreated normal body weight bulimia nervosa women; it also reports foetal and obstetric abnormalities and indicates the initial eating habits of the infants. The prevalence of binge-eating and self-induced vomiting reduced sequentially during each trimester of pregnancy. By the third trimester 15 women (75%) had stopped all bulimic behaviour and in the remainder the disturbed eating was less severe. Symptoms tended to return in the puerperium and in nearly half the sample abnormal eating was more disturbed after delivery than before conception. However, the improvement associated with the pregnancy described by seven patients was maintained and for five it appears to have been curative. The common fear among pregnant bulimics that their abnormal eating behaviour may damage their unborn child cannot be dispelled by this study; the incidence of foetal abnormality (including cleft palate and cleft lip), multiple pregnancies and obstetric complications (including breech presentation and surgical intervention) was high. The nutrition and development of the infants was good although three mothers (15%) reported slimming their babies down within the first year.