Background: Laparoscopic sleeve gastrectomy (LSG) consists of a longitudinal resection of the stomach on the greater curvature, removing 75-80% of the stomach approximately and creating a cylindrical "sleeve"-like conduit. However, LSG can be associated with significant morbidity, and staple-line failure with dehiscence and gastric leak is one of the most severe complications. The aim of this study was to compare three different methods of gastric closure in terms of staple-line strength and leak pressures of the sleeved stomach., Methods: After performing standard stapled sleeve gastrectomies, the gastric specimens were carefully retrieved. Group 1 specimens were left with the staple line intact. In group 2, the staple line was reinforced with a 3-0 polypropylene running suture. The gastric remnants of group 3 were those in which the LSG was performed using Seamguard as the buttressing material. The burst-pressure was assessed using a portable gas sensor. The outcome parameters were: age of the patients, body mass index, buttress material (suture, Seamguard, etc.), leak pressure, volume infused, and leak site, among others., Results: Thirty-six sleeve gastrectomies were included in the final analysis. Each group consisted of 12 gastric specimens. There were no differences between groups in terms of age, sex, body mass index, and patient comorbidities. The leak pressure was significantly higher in group 2 (35 ± 11.7 vs. 102 ± 21.4 vs. 47 ± 19.1; p = <0.0005). The volume of liquid required to cause the leak was much greater in the group 3 (p = <0.001)., Conclusions: Oversewing is the reinforcement method that increases better the staple-line strength. It is the least expensive method of reinforcement and does not increase operative times significantly.