Background: The purpose of the present study was to evaluate the safety, efficacy, and nutritional outcomes of malabsorptive distal Roux-en-Y gastric bypass (D-RYGB) 20-25 years later at a university hospital. Methods: From 1985 to 1989, 49 mostly superobese (body mass index >50 kg/m(2)) patients had undergone D-RYGB. D-RYGB consisted of open laparotomy with a 50-mL proximal gastric pouch and gastroenterostomy performed 250 cm proximal to the ileocecal junction. with common channels of 50-150 cm. These 49 patients were compared with a similar group of 92 consecutive patients who had undergone long-limb RYGB. with a 75-cm biliopancreatic limb and 150-cm alimentary limb. Results: The mean +/- SD preoperative body mass index was 58.9 +/- 9.3 kg/m(2). After 1 perioperative death secondary to pulmonary embolism, limb-lengthening revisions were required in 21 (43.7%) of the 48 remaining patients for protein-calorie malnutrition. Of the 23 with a 50-cm common channel. 13 required revision compared with 8 of 25 with >= 100-cm common channel (P < .05, chi-square). Of the 48 patients who had undergone D-RYGB, 8 had died 6-19 years after D-RYGB. Of the nonrevised patients. 19 (70.4%) of 27 had >5 years of follow-up. In these, the latest body mass index was 34.2 kg/m(2) at 10 +/- 6.1 years. The percentage of excess weight loss was 66.8% +/- 14%. The lowest late serum albumin level was 3.4 +/- .5 g/dL (range 2.3-4.4). The mean 25-hydroxy vitamin D level was 14.6 +/- 11.3 ng/mL. Compared with patients who had undergone RYGB, the D-RYGB patients had a significantly greater percentage of excess weight loss after 5 years but significantly lower albumin. hemoglobin. iron. and calcium levels. Conclusion: Although D-RYGB afforded superior long-term weight loss, it caused protein-calorie malnutrition requiring frequent revision. The nonrevised patients had frequent severe metabolic derangements. Thus. D-RYGB should not be the primary operation for morbid or superobese patients. (Surg Obes Relat Dis 2011;7:189-194.) (C) 2011 American Society for Metabolic and Bariatric Surgery. All rights reserved.