Of 451 deliveries between 1 July 1981 and 30 June 1987, in patients having previously undergone a cesarean section, 279 (62%) were vaginal births, 80 (18%) were primary and 92 (20%) secondary repeat cesareans. The highest frequency of vaginal deliveries was in cases with prior abnormal presentation (87%). History continues to play an important role: vaginal deliveries were achieved in 59% of the cases in which the cesarean section was the only previous delivery. This rate increased to 89% if the subsequent birth was vaginal. Uterine rupture occurred in 10 cases (2.2%). The mode of delivery had no significant influence on the incidence of acidosis; in the repeat cesarean cases the newborns had poorer one-minute Apgar scores.