A detailed analysis of 2632 consecutive pregnancies in white, black and Asian women, who were delivered during the period 1978 to 1980, found significant differences between the three ethnic groups. Asian primiparae had the longest first and second stages of labour, with the highest incidence of prolonged latent phase (14%) and primary dysfunctional labour (30%). Black primiparae and multiparae had the highest incidence of secondary arrest in the first stage of labour (10% and 4% respectively) and of primary dysfunctional labour, with the greatest recourse to emergency caesarean section (13% and 4% respectively). The mean birthweight for singletons born between 37 and 42 weeks was 3.37 kg for white babies, 3.25 kg for black babies and 3.14 kg for Asian babies. There was no racial difference in perinatal mortality or morbidity in this survey.