Background: Improvement in weight control remains the foremost important goal of any treatment program in Prader-Willi syndrome (PWS). To date, bariatric surgery experience in Prader-Willi syndrome (PWS) is proscribed, and different procedures are used with varying success. Malabsorptive procedures, like biliopancreatic diversion (BPD), aren't always recommended for PWS because of lack of safety data and might involve long-term complications. Patients & Methods: We report 10 severely obese patients (6 males) with genetically confirmed PWS (7 del15, 3 UPD15) who underwent Scopinaro’s BPD after inability to regulate food intake with the classical approaches. Surgery was performed on patients aged 18.8±3 yrs. (mean±SD) (range: 15.4-24.4) and also the BMI (kg/m2) was ≥40 all told cases (49.9±6.7). At baseline, severe co-morbidities were present, like obstructive apnea (OSAS), type 2 DM (T2DM), hypertension, metabolic syndrome and/or steatohepatitis. Results: No perioperative complications were observed. After a follow-up period of 13.9±7.3 yrs. (range 4.8-27; mean age at followup: 32.5±6.8 yrs) the most weight leader (MWL%) was 30.7±10 (10.1-52.6). Following BPD, BMI decreased in six patients, stable in three subjects and increased in one individual. The mean BMI at the last visit was 40.5±8.8 (28.9-51.6). After BPD, appetite was reduced in seven cases; eight subjects had hypochromic anaemia and 7 had diarrhea; OSAS were present in 5 patients and osteoporosis/osteopenia altogether individuals. T2DM disappeared and behavioral problems improved in some cases. One patient suddenly died at the age of 37.3 yrs. After surgery all patients received medical therapy to forestall nutritional deficiency. Conclusion: The long-term outcome of BPD in our PWS seems to be favorable, with a big reduction of weight excess within the majority of subjects.