ABSTRACT Objective: to identify the validity of trial of labor in women with second pregnancy and previous cesarean section, to observe vaginal deliverance and probable maternal and perinatal complications. Methods: prospective cohort study of labors (03/2010 - 03/2011). The dependent variables analyzed: vaginal delivery or cesarean section, puerperal and perinatal results complications. The control variables were: epidemiological data, previous maternal and perinatal history, maternal and fetal wellness, labor induction, weekly day and hour of labor, moment of information and birth justification to the patient. The statistical comparison used the chi-squared test with 5% significance and the program Statistical Package for Social Sciences. Results: significance in steady union and married women for cesareans sections, and single in vaginal births (p = 0.004); complete membranes were significant in cesareans sections and rupture of them to vaginal deliveries (p = 0,.001). There was a predominance of cesareans sections during 12:01 - 24:01 hours, and vaginal births from 00:01 - 6:00 hours (p = 0.036). There were no significant events in maternal and fetal complications. Newborns of c-sections were significantly heavier (p = 0.011); extra-uterine vital conditions of 1 and 5 minutes presented no difference between cesarean sections and vaginal births. Conclusion: the trial of labor in 80 patients with second pregnancy and one previous cesarean section avoided the second cesarean section in 42,5% in this patients. The results confirm that trial of labor should be stimulated to labor patients with second pregnancy and one previous cesarean section.