Objectives: External cephalic version (ECV) is a useful method helping to reduce the incidence of planned caesarean deliveries for fetal malpresentation. There is an effort to look for the best predictors for a successful ECV, the effect of maternal weight is still unclear. The aim of our study is to determine maternal body mass index (BMI) in association with the ECV success rate and the risk of complications. Material and methods: A retrospective observational cohort study in 981 women after the 36th week of gestation with a fetus in a breech presentation who had undergone an ECV attempt. We evaluated the success rate and complications of ECV in association with BMI categories according to the WHO classification of obesity. Results: ECV was successful in 478 cases (48.7%). In the category of overweight patients (BMI > 25; n = 484), ECV was successful in 51% and unsuccessful in 49% (p = 0.28) of cases. In obese patients (BMI > 30; n = 187), ECV was successful in 44.8% and unsuccessful in 55.2% (p = 0.28) of cases. The effect of BMI on the success rate of ECV for the category of overweight and obesity was not proven by statistical analysis. Serious complications occurred in seven cases in similar numbers in all three subgroups according to BMI. Conclusions: BMI in the categories of overweight and obesity is not a factor influencing the success rate and risk of complications of ECV. These results can be helpful when consulting pregnant women the chance of successful ECV.