OBJECTIVE: The purpose of this report is to determine the predictable factors for successful vaginal birth after cesarean (VBAC). METHODS: In this study, 382 women who attempted VBAC at Kyung-Hee university hospital were included. The medical records of them were reviewed retrospectively. Informations was collected about demographics, medical history, obstetric history, neonatal birth weight, complications, treatment, and outcome of the index pregnancy. RESULTS: The overall success rate was 76.5% (292 cases). Among variables, neonatal birth weight (odds ratio, 0.2; 95% confidence interval, 0.1-0.4), Bishop score at admission (odds ratio, 1.8; 95% confidence interval, 1.5-2.1 ; p<0.05), and history of vaginal delivery (odds ratio, 3.6 ; 95% confidence interval, 1.1-11.6 ; p<0.05) were significant. The Bishop score showed most significant relationship with successful VBAC. The Bishop score 5 at admission had a sensitivity of 47.4% and a specificity of 87.6% in the prediction of successful VBAC. Malpresentation as indications of previous cesarean delivery showed more tendency to succeed than others. CONCLUSION: Several factors such as birth weight, Bishop score at admission, and history of vaginal delivery may be used to predict the success of VBAC.