A 48-yr-old man was admitted to our hospital with abdominal discomfort and distension. A barium enema showed multiple radiolucent filling defects in the wall of the ascending colon. Colonic endoscopy revealed numerous round, polypoid masses covered with normal mucosa. These findings suggested Pneumatosis cystoides intestinalis. Target air-enema computed tomography was performed to make a final diagnosis, and demonstrated several gas collections covered with soft tissue in the wall of the ascending colon. This is the first reported case of Pneumatosis cystoides intestinalis in which multiple gas-filled cysts could be recognized by target air-enema computed tomography.