Introduction Patients with body mass index (BMI) >= 50 kg/m(2), classified with obesity class IV/V, require complex treatments. Intragastric balloon (IGB) is a possible treatment before metabolic bariatric surgery (MBS) that may reduce peri-operative complications. This study evaluates IGB outcomes and complications before MBS in patients with Obesity IV/V, and subsequent MBS results, regarding weight loss and comorbidity resolution. Methods Retrospective cohort study of all patients with BMI above 50 kg/m(2) submitted to IGB before MBS between 2009 and 2023 in a high-volume center. Variables analyzed included weight loss after IGB and MBS, IGB complications, and comorbidity resolution. Suboptimal clinical responses were defined as %TWL < 5% for IGB, %TWL < 20% for MBS, and %TWL < 25% or BMI >= 35 kg/m(2) for IGB + MBS<bold>.</bold> Results Seventy-four patients (mean BMI 58.8 +/- 8 kg/m(2)) were included. After IGB, the mean %TWL was 14.2 +/- 8.5%, with a 21.6% complication rate, predominantly nausea and vomiting, and one death. Suboptimal clinical response of IGB affected 13.5% of patients, and 5.4% required early removal. Two years after MBS, the mean %TWL was 38.2 +/- 11.6%, mainly due to MBS, yet approximately one-third of %TWL was attributed to IGB. No correlation was found between IGB and MBS outcomes. At 2-year follow-up, 45.1% patients had %TWL >= 25 and BMI < 35 kg/m(2). Conclusion The IGB is a treatment option before MBS in patients with Obesity Class IV/V, with acceptable weight loss outcomes but not infrequent complications. A multidisciplinary approach is mandatory, and all treatments must be considered in this difficult subset of patients.