Single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a new operation for morbid obesity based on the biliopancreatic diversion in which a sleeve gastrectomy is followed by an end-to-side duodeno-ileal diversion. The preservation of the pylorus makes possible the reconstruction in one loop, which reduces operating time and needs no mesentery opening. We review the results obtained on the first 50 operated patients with 1 to 3 years follow-up. Eighteen men and 32 women with a mean BMI of 44 kg/m(2) were operated on. Hypertension was present in 50%, sleep apnea in 30%, hypertriglyceridemia in 60% and hypercholesterolemia in 43%.There were 27 type two diabetics, most of them on insulin therapy. There were two gastric staple-line leaks and one long-term subphrenic abscess. Follow-up is complete for 98% of the patients. Excess weight loss reached 94.7% at 1 year, and it was maintained over the second and third year. At 1 year, mild anemia has been detected in 10% of the cases. Albumin concentration was under normal levels in 8% of the patients in the first postoperative year, but all patients recovered to normal levels by the third postoperative year. All diabetic patients have normalized glucose or HbA1c levels after the sixth postoperative month with no need of anti-diabetic therapy. SADI-S is a promising operation which offers excellent weight loss and metabolic results. The elimination of one anastomosis reduces operative time and decreases the possibility of surgically related complications.