Weight regain or inadequate weight loss following Roux-en-Y gastric bypass poses a significant clinical challenge. Our objective was to evaluate various revisional techniques for addressing weight regain and insufficient weight loss after Roux-en-Y gastric bypass through a systematic review and meta-analysis. We performed a literature search (in PubMed and Embase) on revisional interventions in collaboration with a medical information specialist. Measured outcomes included body mass index at intervention, total weight loss during follow-up, and complications. Random effects models were used to determine pooled effect size and corresponding 95% confidence intervals. Thirty-nine studies were included: four studies reported on argon plasma coagulation, four studies on transoral outlet reduction, nine studies on transoral outlet reduction + argon plasma coagulation, four studies on pouch/gastrojejunal anastomosis revision, five on laparoscopic gastric banding, two studies on laparoscopic gastric banding + pouch resizing, 10 on distalization-RYGB, and one on duodenal switch. All techniques resulted in short-term clinically relevant weight loss. Endoscopic procedures had a short follow-up and resulted in modest and temporary weight loss. Surgical revision techniques were successful for weight loss in longer term follow-up, at the expense of high complication rates.