BACKGROUND It is unusual for a patient to manifest both morbid obesity and hyperlipidemia. Certain of these individuals may also have a history of hypertriglyceridemic pancreatitis. We report six morbidly obese hypercholesterolemic patients, two with recurrent hypertriglyceridemic pancreatitis, who were managed by concurrent gastric restrictive surgery and a partial ileal bypass operation. METHODS The first dual procedure was performed on January 6 1992, and the most recent on February 20 1997. Our series consists of two males and four females, with an average age of 35.5 years at the time of surgery. The mean preoperative weight of these patients was 116.8 kg, and the mean BMI was 39.7 kg/m2. The preoperative mean total plasma cholesterol was 5.5 g/l and the mean plasma triglyceride was 30.61 g/l; the two patients with a history of hypertriglyceridemic pancreatitis had plasma triglyceride levels of 33.6 g/l and 65 g/l. RESULTS The average weight reduction, using available follow-up intervals was 40.3 kg (34.5%), with a mean postoperative BMI of 20.0 kg/m2 (34.8% reduction). The markedly elevated total plasma cholesterol and plasma triglyceride levels were normalized, with a postoperative mean total plasma cholesterol of 1.47 g/l (73.3% reduction) and a concomitant mean plasma triglyceride of 1.63 g/l (94.7% reduction). The two patients with a history of pancreatitis sustained triglyceride reductions of 96.5% and 94.1%, and neither patient has had an episode of pancreatitis following the dual operative procedures. CONCLUSIONS We conclude that the combination of a gastric restrictive operation with a partial ileal bypass procedure represents excellent management for patients with both morbid obesity and hypercholesterolemia, especially if the hypercholesterolemia is accompanied by hypertriglyceridemic pancreatitis.