PURPOSE: The Single Anastomosis Sleeve Ileal (SASI) bypass is a novel bariatric procedure that simplifies Santoro's procedure, balancing functional restriction and neuroendocrine modulation while preserving anatomy. We aim to conduct a single-arm meta-analysis of the SASI bypass to explore its moderate-term efficacy, as this might expand the available choices for surgeons to choose the best bariatric surgery that suits the patient's condition. MATERIALS AND METHODS: We conducted a comprehensive search on PubMed, Scopus, EMBASE, and Cochrane to identify studies for the SASI bypass surgery focusing on outcomes such as %EWL, %TWL, remission rate of comorbidities, and complications. The statistical analysis was carried out using RStudio version 4.3.2. Heterogeneity was assessed using the Cochrane Q test and I statistics. RESULTS: Our findings illuminate SASI's potency by undertaking a single-arm meta-analysis involving 1873 patients across 26 studies. At 12 months, we report a noteworthy % Excess Weight Loss (%EWL) (Mean 84.13; 95% CI 78.41-89.85; I = 95%), and % Total Weight Loss (%TWL) (Mean 35.17; 95% CI 32.30-38.04; I = 97%), highlighting SASI's efficacy on weight loss. Cumulative meta-analyses supported these findings. More weight loss was observed with a 250 cm common limb and a greater than 3 cm anastomosis. An 88.28% remission rate in type 2 diabetes mellitus (95% CI 79.74-95.03; I = 84%) at 12 months was observed. Beyond weight outcomes, SASI impacts comorbidities with a good safety profile. CONCLUSION: Our study positions the SASI bypass as a good alternative option. However, long-term efficacy is yet to be explored in the future.