Our purpose was to determine the impact of labor induction on both the success and safety of a trial of labor in women who are candidates for vaginal birth after cesarean.We performed a prospective observational analysis of 505 women consecutively presenting for delivery with a prior cesarean (September 1997-December 1999), of whom 236 (46.7%) underwent trial of labor. The following three cohorts were established: (1) repeat cesarean without trial of labor (n = 269), (2) spontaneous trial of labor (n = 179), and (3) induced trial of labor (n = 57).The vaginal delivery rate was significantly higher (77.1% vs 57.9%) in the spontaneous labor group compared with the induced labor group (odds ratio, 2.45; 95% confidence interval, 1.24-4.82; P =.008). Uterine scar separation occurred more frequently in the induced labor group (7%) than in the elective repeat cesarean group (1.5%) (odds ratio, 0.20; 95% confidence interval, 0.04-0.99; P =.034).Induction of labor in women attempting vaginal birth after cesarean is associated with a significantly reduced rate of successful vaginal delivery and an increased risk of serious maternal morbidity.