Background: The Bioenterics Intragastric Balloon (BIB) has been a safe and effective method used in treatment of moderate obesity. Gastric perforation is a rare complication, and its possible sequelae are dangerous. Methods: A 52-year-old women (BMI 37 kg/m(2)), with hiatal hernia, moderate hypertension and dyspnea, 1 year ago underwent laparoscopic fundoplication. She now underwent positioning of a BIBO filled with 500 cc of saline. After 8 days, 6 kg weight loss occurred and her clinical condition was satisfactory. On day 11, severe abdominal pain and vomiting occurred, which spontaneously regressed in the following 6-8 hours. Ultrasound confirmed the correct position of the BIBO, and showed widespread abdominal meteorism. On day 18, acute abdomen with paralytic ileus occurred. On admission, CT scan documented hydropneumoperitonitis. At operation, a large perforation of the lesser curvature was found, with undigested food in the abdomen. She underwent peritoneal lavage, removal of the BIB, and suture of the gastric laceration. Results: She was discharged in good condition after 11 days. Conclusion: According to our experience, fundoplication represents an absolute contraindication to positioning of a BIB(R).