Cesarean section is now the most frequently performed major operation in the United States. Nearly one out of every four American babies is delivered by this operation. "Elective repeat" has become the most common indication for cesarean section. Although the safety of vaginal birth after cesarean section has been documented in several recent publications, automatic repeat cesarean section remains the rule in this country. We present one of the largest series of trial of labor ever reported. Of 57,553 live births, 4929 (8.6%) were of women with prior cesarean sections. Among 1776 patients who underwent a trial of labor, 1314 (74%) delivered vaginally. There was no maternal or perinatal mortality related to uterine scar rupture. Thus during the study period 1314 major operations were avoided. We conclude that, for the vast majority of women, allowing a trial of labor is a safe alternative to automatic elective repeat cesarean section.