BACKGROUND: The duodenal switch (DS) is a variant of the biliopancreatic diversion (BPD), with a vertical subtotal gastrectomy and pylorus preservation. METHODS: DS was used to treat morbid obesity in 125 patients, with mean BMI 50, with 65% of the patients super obese (SO). Patients have been followed for an intermediate period. RESULTS: The percentage of excess weight loss (%EWL) was > 70% at 1 year, and reached 81.4% at 5 years when 97% of the patients had a %EWL > 50%. Comorbidities were cured or improved in all patients. CONCLUSION: DS was very effective for the treatment of the morbid obesity in the SO patients.