An 81-year-old male patient was referred to our hospital with abdominal pain and vomiting. Physical examination of the abdomen revealed both tenderness and rebound tenderness over the entire abdomen. Enhanced abdominal CT demonstrated free air in the upper abdomen and bladder wall emphysema in the pelvis. The findings led to the suspicion of upper gastrointestinal perforation, and emergency surgery was performed on the same day. While laparoscopic intraperitoneal exploration revealed no upper gastrointestinal perforation, a perforation was confirmed in the wall of the bladder on the right side. The bladder wall was sutured laparoscopically, and the abdominal cavity was irrigated with 3,000 mL of normal saline. No complications were observed after the operation, although the patient was in the hospital for 35 days after the surgery for rehabilitation. This case underscores the need to bear in mind the possibility of bladder rupture in the differential diagnosis of patients presenting with acute abdomen with free air in the abdomen. Herein, we report a case of bladder rupture associated with emphysematous cystitis who underwent emergency surgery under the diagnosis of gastrointestinal perforation.