The placement of an intragastric balloon (IGB) plays an increasingly important role in the treatment of obesity. The authors describe the cases of 2 female patients, 34 and 62 years old, who were submitted to the implantation of a Spatz3® IGB to treat obesity. Ten to fourteen weeks later, the patients presented complaints of epigastric pain, vomiting, and abdominal distension. A bulging of the upper abdominal wall was noticed upon physical examination. Upper gastrointestinal endoscopy confirmed the clinical suspicion of IGB hyperinflation. It was decided to remove the 500 mL of saline solution with methylene blue from inside the balloon. During the same procedure, the IGB was refilled with 500 mL of fresh saline solution, methylene blue, and empiric β-lactam antibiotic. The extracted content of the hyperinflated IGB was sent for microbiological culturing and was found to be positive for <i>Streptococcus viridans</i> in one of the cases. In the other case, the culture examination was negative, and after 8 weeks, the patient presented again with hyperinflation of the IGB. It was then decided to substitute the IGB with another balloon; the procedure was uneventful. The content of the removed IGB was sent for microbiological testing, and colonization by <i>Candida tropicalis</i>was confirmed. This is a rare but potentially serious complication of IGB placement. Randomized trials are needed to clarify the role of antibiotics and antifungals in primary and secondary prophylaxis against IGB hyperinflation.