Guiding patients with type 2 diabetes (T2D) toward the most appropriate bariatric and metabolic procedure is crucial for improving outcomes. In recent years, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) have been the most commonly performed bariatric procedures worldwide. Both are safe, effective, and durable metabolic procedures. The aim of this review was to critically examine the best available evidence derived from the randomized clinical trials (RCTs) to identify which bariatric procedure is superior in an individual with T2D to provide sustainable long-term remission. There are 4 RCTs in patients with T2D that directly compare RYGB with SG, report outcomes up to 5 years after randomization, and provide level I evidence for procedure selection. While the remission rate of T2D after RYGB versus SG is comparable in all 4 RCTs, all studies are underpowered to reveal differences in T2D-related endpoints between these 2 procedures. Combined analysis of RCTs (RYGB, n = 176 versus SG, n = 175) would indicate that either there is no significant long-term difference between RYGB and SG in improving T2D, or in case of a true difference (and we still do not have enough statistical power to reveal the difference), that difference would be <15% favoring RYGB. Prediction tools, such as the individualized metabolic surgery score, can identify patients who can benefit the most from the antidiabetic effects of RYGB. Nonetheless, the procedure selection should not be solely based on T2D-related outcomes. Diabetes is one outcome; one of many outcomes that needs to be considered in decision-making. Patient's conditions and clinical outcomes that are critical in choosing the most optimal bariatric and metabolic procedure will also be explained in this review. (C) 2019 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.