OBJECTIVE To assess the prevalence of cesarean section (CS) related maternal complications and to evaluate post-CS complications in relationship with relative risk factors. METHODS 3010 patients who had a CS in the University Hospital of Bari during the period 1988-98 were retrospectively included into the study and 1007 women delivered vaginally at the same institution and in the same period of time, were randomly selected as the control group. For each single patient delivered by CS, the following risk factors were taken into account: age, parity, pre-pregnancy body mass index (BMI), and any disease antedating pregnancy or diagnosed during pregnancy. Additionally, therapeutic procedures such as blood transfusion, number of days in hospital, and admission into intensive care were followed. The prevalence of puerperal complications was assessed for vaginal deliveries and CS by Student's t-test and a correlation of CS complications with risk factors was performed by multivariate analysis. RESULTS In the cohort of abdominal delivery, puerperal complications were significantly more frequent compared with those following vaginal delivery (p < 0.05). In the group of CS, obese women have higher prevalence of maternal complications, particularly hypertension and intestinal complications (p < 0.05). CONCLUSIONS Compared with vaginal delivery, CS delivery carries a higher number of postpartum complications, and the higher rate is mainly related to obesity.