Background: Laparoscopic One Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y gastric Bypass are two of the most common bariatric techniques.We compared quality of life in both procedures, assessing pre-operative and long term post-operative differences in quality of life, physical activity level and psychosocial functioning in patients undergoing bariatric surgery.Methods: A prospective cohort study including obese patients undergoing either Laparoscopic One Anastomosis Gastric Bypass or Laparoscopic Roux-en-Y gastric Bypass.The Moorehead-Ardelt Quality of Life Questionnaire II and Gastrointestinal Quality of Life Index (GIQLI) questionnaires were administered at 3 months preoperatively and 3 years after surgery, while the third, the Bariatric Analysis and Reporting Outcome System (BAROS), was administered only postoperatively.Results: A total of 41 patients were included in the study.Statistically significant differences were found between the Moorehead-Ardelt Quality of Life Questionnaire II and QIGLI scores taken at both time points, across the entire cohort (p= 0.001 and p= 0.001, respectively); and between the results taken at 3 years postoperatively in the BAROS test (p= 0.001) for the entire cohort.There were no significant differences between Laparoscopic One Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y gastric Bypass groups in the questionnaire scores (Moorehead-Ardelt Quality of Life Questionnaire II: p=0.526,QIGLI: p=0.990 and BAROS: p=0.753).Conclusions: Bariatric surgery improves quality of life in operated patients, without significant differences between Laparoscopic One Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y gastric Bypass techniques.Patients undergoing bariatric surgery develop higher physical activity levels, and long-term improvements in the psychosocial domain are observed over time.