Examine safety of TVT-O.Experimental study.Gynekologicko-porodnická klinika 1. LF UK a VFN, Institute of Anatomy, Institute of Pathology LF U.K., Praha.We inserted TVT-O in fourteen formalin-embalmed bodies with legs mal-positioned. After dissection distances from the branches of obturator nerve to the inserter were measured.In embalmed bodies, the mean distance to the anterior branch of the obturator nerve was 8.6 mm on the left, 7.1 mm on the right. Mean distance to the posterior branch of the obturator nerve was 8.4 mm on the left, 8.9 mm on the right.The position of the legs is crucial for correct placement of TVT-O.