Aim: To evaluate weight loss and surgical outcomes of Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric band (LAGB). Methods: Data relating to changes in body mass index (BMI) and procedural complications after RYGB (1995-2009; n = 609; 116M: 493F; 42.4 ± 0.4 years) or LAGB (2004-2009; n = 686; 131M: 555F; 37.2 ± 0.4 years) were extracted from prospective databases. Results: Pre-operative BMI was higher in RYGB than LAGB patients (46.8 ± 7.1 kg/m 2 vs 40.4 ± 4.2 kg/m 2 , P < 001); more patients with BMI < 35 kg/m 2 underwent LAGB than RYGB (17.1% vs 4.1%, P < 0.0001). BMI decrease was greater after RYGB. There were direct relationships between weight loss and pre-operative BMI (P < 0.001). Although there was no difference in weight loss between genders during the first 3-year post-surgery, male LAGB patients had greater BMI reduction than females (-8.2 ± 4.3 kg/m 2 vs -3.9 ± 1.9 kg/m 2 , P = 0.02). Peri-operative complications occurred more frequently following RYGB than LAGB (8.0% vs 0.5%, P < 0.001); majority related to wound infection. LAGB had more long-term complications requiring corrective procedures than RYGB (8.9% vs 2.1%, P < 0.001). Conversion to RYGB resulted in greater BMI reduction (-9.5 ± 3.8 kg/m 2 ) compared to removal and replacement of the band (-6.0 ± 3.0 kg/m 2 ). Twelve months post-surgery, fasting glucose, total cholesterol and low density lipoprotein levels were significantly lower with the magnitude of reduction greater in RYGB patients. Conclusion: RYGB produces substantially greater weight loss than LAGB. Whilst peri-operative complications are greater after RYGB, long-term complication rate is higher following LAGB.