BACKGROUND Biliopancreatic diversion (BPD), by ad hoc stomach resection (AHS-BPD) has been accepted as an effective surgical treatment for morbid obesity. METHODS Between 1.1.1992 and 31.7.1996, 59 patients (54 females, five males, mean age 40.3 years, range 23-61 years) underwent AHS-BPD. Mean preoperative body-weight was 121.2 kg (range 94-160), with a mean body mass index of 48.6 (range 35-64). Three of these patients were converted from a previous vertical banded gastroplasty to AHS-BPD (one patient with stomach preservation). After at least 36 months follow-up, seven patients underwent abdominal dermolipectomy (five with associated incisional hernia repair, one with thigh dermolipectomy). RESULTS Mean post-operative hospital stay was 13 days (range 10-30 days). Follow-up is currently in progress in all patients. Excess body weight-loss was 78% in 33 patients with 24 months follow-up, with excellent long-term weight loss maintenance. Protein deficiency was the main specific complication, encountered in two patients (3.4%). Mortality was one patient (1.7%), due to pulmonary embolus. CONCLUSIONS This clinical experience supports the effectiveness and safety of AHS-BPD, despite some criticism. This procedure appears to be suitable for patients with clinically severe obesity who will poorly tolerate food intake restriction but will accept long-term follow-up. Careful preoperative clinical assessment and selection of patients who will be reliable in long-term follow-up are the keys to success with AHS-BPD, both in terms of weight loss and reduction of specific metabolic complications.