Pneumatosis (cystoides) intestinalis is defined as the presence of gas in the bowel wall and can be found anywhere in the gastrointestinal tract. It may be harmless or life-threatening, depending on the etiology which includes infectious and drug-induced colitis, bowel ischemia and necrotizing enterocolitis. The lesion has additionally been described following endoscopy. We report two cases of asymptomatic pneumatosis coli mimicking polyposis syndrome or malignancy. Both cases were verified histologically after snare polypectomy or hemicolectomy. The differential diagnosis and the clinical significance of the disease are discussed. Accurate diagnosis, which is mainly based upon endoscopy, computed tomography and histology, is crucial for optimal patient management thus avoiding unnecessary surgical procedures.