The aim of this study was to compare silicone-banded sleeve gastrectomy (BSG) to nonbanded sleeve gastrectomy (SG) regarding weight loss, obesity-related comorbidities, and complications. As a primary bariatric procedure, SG leads to excellent weight loss, yet weight regain is a relevant issue in mid- to long-term follow-up. Retrospective analyses suggest that banding a sleeve using a silicone ring may decrease weight regain and improve weight loss. The banded versus nonbanded sleeve gastrectomy single-center, randomized controlled trial was conducted from January 2015 to August 2019. The primary endpoint was defined as excess weight loss 3 years after surgery. Secondary endpoints included the surgery's impact on obesity-related comorbidities, quality of life, and complications. The study was registered under DRKS00007729. Among 94 patients randomized, 97% completed 3-year follow-up. Mean initial body mass index was 50.9 kg/m [95% confidence interval (CI), 49.6-52.2]. Mean adjusted excess weight loss 3 years after SG amounted to 62.3% (95% CI, 56.2-68.5) and 73.9% ( 95% CI, 67.8-80.0) after BSG (difference 11.6%, P = 0.0073). Remission of type 2 diabetes occurred in 66.7% (4/6) after SG and in 91.0% (10/11) following BSG (P = 0.21). Three years after surgery, ring implantation correlated with decreased frequency of symptomatic reflux episodes (P = 0.01) but increased frequency of regurgitation (P = 0.03). The rate of major complications was not different between the study groups (BSG, n = 3; SG, n = 2; P = 0.63). Quality of life was better following BSG (P = 0.001). BSG provided better weight loss than nonbanded SG 3 years after surgery. Regurgitation was the main clinically relevant negative effect after BSG.