SummaryPneumatosis cystoides intestinalis is a rare disease with an acute or subacute clinical presentation. Here, we present two cases seen at our institution over a 5-year period. The first patient underwent emergent laparotomy due to abdominal extraluminal free air caused by ruptured pneumatosis cystoides intestinalis, which may be related to the use of alpha-glucosidase inhibitors. No perforation of the ascending colon was identified during the operation. Multiple sigmoid pneumocysts mimicking colonic polyposis were found in the second patient, who underwent sigmoidectomy for excluding colonic malignancy. We emphasize the importance of correct diagnosis of pneumatosis cystoides intestinalis and optimal management to prevent unnecessary surgical treatment.