Objective:To report a prospective multicenter comparison of outcomes of patients who attempted trial of labor and those who underwent elective repeat cesarean.Methods:During the study interval, all pregnant women with previous cesarean delivery cared for at Kaiser Permanente Hospitals in Southern California were studied regardless of whether trial of labor or elective repeat cesarean was planned.Results:Of 7229 study patients, 5022 (70%) had a trial of labor and 2207 had elective repeat cesarean operations. Seventy‐five percent (3746) of those opting for trial of labor went on to deliver vaginally. The rate of uterine rupture was less than 1% and there were no maternal deaths related to uterine rupture. The hospital length of stay, incidence of postpartum transfusion, and incidence of postpartum fever were all significantly higher in the elective repeat cesarean group than in the trial of labor group.Conclusions:Labor after previous cesarean delivery has a 75% success rate, with a risk of uterine rupture of less than 1%. Neither repeat cesarean delivery nor trial of labor is risk‐free. With careful supervision, trial of labor eliminates the need for a large proportion of repeat cesarean operations.(Obstet Gynecol 1994;83:927‐32)