We report a case of idiopathic pneumoperitoenum in a 75-year-old male who presented to the Emergency Department with vague left-sided abdominal pain. There was no history of recent trauma. Exploratory laparotomy was negative. He made an uneventful post-operative recovery and was discharged home 6 days after the exploratory laparotomy. A repeat chest X-ray done prior to discharge showed no evidence of a pneumoperitoneum.