BackgroundUntil recently, Roux-en-Y gastric bypass (RYGB) was the most frequently performed procedure in bariatric surgery. In the last decade, sleeve gastrectomy (SG) has emerged as a more popular, simpler, and less morbid form of bariatric surgery. ObjectivesThis study compares the efficacy of SG and RYGB for the treatment of type 2 diabetes mellitus (T2D). SettingSystemic review and meta-analysis. MethodsMEDLINE, EMBASE, and the Cochrane Library were searched for entries up to December 2013. Search terms included “Sleeve gastrectomy,” “Gastric bypass,” and “Type 2 diabetes mellitus.” The chosen articles described both “Sleeve gastrectomy” and “Gastric bypass” and included over 1 year of follow-up data. Data analysis was performed with Review Manager 5.2 and SPSS version 20. ResultsThe data set is comprised of 3 retrospective clinical studies, 6 prospective clinical studies, and 2 randomized controlled trials (RCTs), which involved 429 patients in the SG group and 428 patients in the RYGB group. In nonrandomized clinical studies, SG displayed similar efficacy in remission of T2D compared with the standard RYGB. In the RCTs, SG had a lower effect than that of RYGB. T2D remission was not correlated with the percent of excess weight loss for either procedure. ConclusionsBased on the current evidence, SG has a similar effect on T2D remission as RYGB.