OBJECTIVE: To apply published scoring systems retrospectively to patients who had undergone a trial of labor after cesarean delivery to estimate whether there was a score at which a trial of labor should be discouraged. METHODS. Patients with 1 previous cesarean delivery whothen delivered between January 1, 1998, and December 31, 1998, were studied. An investigator blinded to outcome assigned scores using 3 different scoring systems. Student t test, X, analysis of variance, and receiver operating curve analysis were performed. P < .05 was significant. RESULTS: Seventy-six percent (117/153) of trial of labor patients had a vaginal birth after cesarean delivery. Successful vaginal birth after cesarean delivery patients had significantly different mean scores using all 3 scoring systems, but none of the systems accurately predicted failed trial of labor resulting in cesarean delivery. Unfavorable scores were associated with high rates of major complications. CONCLUSIONS: An unfavorable score predicting a high rate of complications and more failed trials of labor may help in counseling patients considering trial of labor. A better system to predict the success or failure of trial of labor is needed. (C) 2004 by The American College of Obstetricians and Gynecologists.