Introduction: There are only few reports regarding the use of intragastric-balloons (IGB ® ) to achieve weight loss and subsequently decrease surgical complications. In this study, we try to assess whether presurgery weight loss using IGB decreases the postsurgical mortality after bariatric surgery.Material and methods: This is a prospective case-control study. We matched 1:1 by gender, age (± 10 y-o) and type of surgery (sleeve resection [LSG] or gastric bypass [LGBP]), matching cases (A) and controls (H, from a historic cohort). Morbidly obese patients with an indication for bariatric surgery were included in the study. Cases (A) were recruited from an ongoing clinical trial, and the controls (H) came from a historic cohort prior to the start of the clinic trial. The presurgical weight loss in group A was reached by IGB combined with diet, versus only diet in group H.Results: We included 58 patients, 65.5% women, 69% LGBP/31% LSG. The mean age of group A was 42 and 43.4 years old for group H. ASA III of 24.1% group A vs 58.6% group H, p = 0.012. The mean total weight loss (TWL) before surgery was greater in group A (16.2 kg, SD 9.75) than in group H (1.2 kg, SD 6.4), p < 0.0001. The % of EWL before surgery was 23.5 (SD 11.6) in group A vs 2.4 (SD 8) in group H, p < 0.001. Hospital stay was seven days for group A, and eight days for group H, p = 0.285. The rate of unsuccessful IGB treatment to accomplish the scheduled weight loss was 34.5%. The balloon morbidity was 17.2% (6.9% severe). All in all, morbidity (due to bariatric surgery and IGB) was 41% in both groups. Postsurgical morbidity moderate-severe was 20.3% in group A (6.9% severe) and 27.3% in group H (17.2% severe) without statistical significance. One patient died in group H (mortality rate, 3.44%).Conclusion: Preoperative IGB treatment in morbid obesity has not been found to be effective at decreasing postsurgical morbidity LSG and LGBP, despite the fact that it acheives a greater weight loss than diet and exercise.