Introduction: The duodenal switch (DS) technique is considered to be complex surgery with a series of metabolic complications due to its malabsorptive character. For these reasons, it has not been extensively used by bariatric surgeons. Despite this, we consider it to be a suitable technique for the grossly obese. Patients and methods: A retrospective study was performed on 110 patients with morbid obesity operated on using the DS technique and who were followed up for a minimum period of four years after surgery. We evaluated the weight loss, the outcomes of the comorbidities, and the metabolic complications. Results: The loss of excess weight was greater than 50% in 75% of the patients after 12 months follow up. The comorbidities suffered by 68 patients (75.5%) were completely resolved. The most frequent metabolic complications were iron (Fe) deficiency and an increased parathyroid hormone (PTH). Conclusions: DS is a safe and effective technique for the treatment of morbid obesity, with good weight loss results, a high percentage of remission of the comorbidities, a similar morbidity and mortality to other techniques, and with correctable nutritional changes, and thus acceptable. (C) 2011 AEC. Published by Elsevier Espana, S.L. All rights reserved.