Objective. —To determine the independent effect of socioeconomic, organizational, and professional liability factors on the odds of vaginal birth after cesarean delivery (VBAC) while controlling for important clinical factors. Design. —A retrospective study of 1989 New York State vital statistics data, supplemented with additional information on county- and hospital-specific variables. Using multiple logistic regression analysis, odds ratios (ORs) and 95% confidence intervals (CIs) were derived for 15 independent variables. Setting. —Births occurring in 104 New York State hospitals. Data Set. —A total of 13944 births occurring to New York State residents with a history of cesarean delivery of which 3068 (22%) were vaginal deliveries. Results. —The odds of VBAC increased with maternal education. The ORs were 1.15 (95% CI, 0.99 to 1.34) for 12 years of education; 1.36 (95% CI, 1.16 to 1.60) for 13 to 15 years; 1.59 (95% CI, 1.32 to 1.93) for 16 years, and 2.00 (95% CI, 1.64 to 2.45) for 17 years or more. The ORs also increased with the level of care provided by the hospital; they were 1.55 (95% CI, 1.34 to 1.81) and 1.30 (95% CI, 1.18 to 1.44) for hospitals with intensive and intermediate neonatal care facilities, respectively. The ORs were 1.15 (95% CI, 1.02 to 1.30) for health maintenance organization participants and 0.77 (95% CI, 0.63 to 0.94) for women giving birth in government hospitals. The ORs of VBAC for African-American and Hispanic mothers were 0.80 (95% Cl, 0.70 to 0.93) and 0.61 (95% CI, 0.51 to 0.73), respectively. The ORs for a $5000 increase in physician's yearly malpractice premium and the hospital's paid loss due to malpractice claim settlements were 0.98 (95% CI, 0.97 to 0.99) and 1.01 (95% CI, 0.99 to 1.03), respectively. Conclusions. —In addition to clinical factors, a mother's level of education and ethnicity and specific characteristics of the hospital in which she delivers affect the odds of a vaginal delivery after a previous cesarean delivery. From our analysis, we cannot conclude that professional liability factors affected VBAC rates. (JAMA. 1994;272:524-529)