Objective:To examine several variables that may affect the success rate for a trial of labor after previous cesarean delivery, as well as those affecting the rate of uterine rupture.Methods:Between June 1, 1990 and December 31, 1991, we performed a consecutive, prospective study of 593 pregnant women who had had at least one abdominal delivery in the past, and attempted a trial of labor in each. Particular attention was given to the success rate of vaginal delivery, the type of previous uterine incision, use of oxytocin, estimated maternal blood loss, 5‐minute Apgar scores, and reason for the previous cesarean operation.Results:Four hundred seventy‐eight patients (81%) had a successful vaginal delivery. Oxytocin induction or augmentation was successful in 46 of 67 (69%) and 117 of 167 cases (70%), respectively. Estimated maternal blood loss was less than 500 mL in 453 cases (95%). Five patients (0.8%) experienced true uterine rupture, resulting in severe neurologic sequelae in one infant. The only consistent indication of uterine rupture was an abrupt and prolonged fetal bradycardia. The majority (463; 97%) of infants who were delivered vaginally had 5‐minute Apgar scores of 8 or greater.Conclusion:Our success rate of 81% suggests that a trial of labor after previous cesarean delivery is a safe and desirable option, but only after thorough patient counseling. An abrupt and persistent fetal bradycardia may be the only indication that uterine rupture has occurred.(Obstet Gynecol 1994;83:933‐6)