Background: Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) are frequently used bariatric procedures. With both techniques, LAGB more than RYGB, failures occur. After years of experience with both techniques, we present a series of patients who underwent RYGB after failed LAGB. The band was kept in place. Our objective was to evaluate the safety and short-term effectiveness of RYGB after failed LAGB, without removing the band. The setting was a large teaching hospital in Heerlen, The Netherlands. Methods: We first retrospectively considered the efficacy and complication rate of adding an adjustable band to RYGB. This was safe and effective. The patients lost a median of 7.6 kg within a median period of 21 months. The complication rate was low. Observing the positive results in this group, we began to leave the band in place when converting patients from LAGB to RYGB. Results: A total of 12 patients underwent revision of LAGB to RYGB. There was no modality. The complication rate and severity were low. During a median period of 16 months, the patients lost a median of 23 kg or 8 points in the body mass index. Also, additional improvement in co-morbidities was observed. Conclusion: Our results suggest that performing RYGB after LAGB and leaving the band in place is feasible, safe, and effective in the short term. (Surg Obes Relat Dis 2012;8:717-723.) (C) 2012 American Society for Metabolic and Bariatric Surgery. All rights reserved.