OBJECTIVE The aim of this study is to compare the material effectiveness of oversewing the staple line following laparoscopic sleeve gastrectomy. METHODS A prospective randomized trial has been performed on 100 consecutive patients who underwent laparoscopic sleeve gastrectomy. Just before the intervention patients were randomized to receive (Group A) or not receive (Group B) a polypropylene 3-0 running oversewing suture of the staple line. RESULTS By evaluating preoperative general demographics features and co-morbidities between group A and group B no statistical difference was observed. Main complications evaluated were fistol, bleeding and stenosis and there were no significant difference in fistulas occurrence (p = 0.55) and bleeding (p = 0,65) while on the other hand it has to be remarked how sleeve stenosis has been significantly higher when oversew is performed (p = 0.04). CONCLUSIONS Staple line leakage is a worrisome complication of laparoscopic sleeve gastrectomy (LSG). Despite some reports describe oversewing of the staple line as the solution to prevent such problem; other authors have demonstrated the incidence of leaks being the same in oversewed and not oversewed patients. CONCLUSIONS This randomized trial has so far shown oversew of LSG to be significantly useless to prevent fistulas formation in patients selected according to our study design.