Background Biliopancreatic diversion with duodenal switch (BPD/DS) is the most effective bariatric surgery in super-obese patients, although technically complex and time consuming. As a primary surgery, single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is similar to BPD/DS in terms of short-term outcomes, but long-term and comparative data are lacking. Objectives The aim of this study was to compare the outcomes of patients submitted to SADI-S and BPD/DS. Setting Public hospital. Methods Obese patients (n = 112) submitted to SADI-S (n = 83) and BPD/DS (n = 29) for obesity treatment were prospectively compared. Results The mean preoperative body mass indexes (BMIs) were 53.41 ± .93 for BPD/DS and 50.61 ± .52 kg/m2 for SADI-S. Follow-up of 48 months was achieved in 18% (n = 21) of patients, with a nonsignificant difference in the percentage of excess BMI loss (%EBMIL; 81.20 ± 3.71 for BPD/DS; 74.82 ± 3.45 for SADI-S). Operative time (164.30 ± 7.78 minutes for BPD/DS; 132.70 ± 7.19 minutes for SADI-S; P = .006) and hospital stay (4.90 ± 1.10 days for BPD/DS; 4.35 ± .70 days for SADI-S; P = .006) were significantly shorter for SADI-S. There was no significant difference in the 30-day postoperative complication rate. No mortality was reported. After surgery, significant improvements were observed in glucose and lipid profiles for both groups. The type 2 diabetes remission rate was 100% for BPD/DS and ranged from 60 to 80% for SADI-S across follow-up times. Dyslipidemia remission followed a similar pattern. Protein deficiency was observed in up to 50% of patients after BPD/DS and 20% after SADI-S, without statistically significances. Conclusion SADI-S and BPD/DS as primary surgery for obesity treatment result in no significant differences in %EBMIL, improvement in obesity-related diseases, nutritional deficiencies, and postoperative morbidity. Nevertheless, there was greater total weight loss after BPD/DS. SADI-S, being less time consuming and technically simpler, can represent an advantage over BPD/DS.