Perforation peritonitis is an important cause of generalized peritonitis and pneumoperitoneum. Large bowel perforation due to swallowed artificial denture is extremely rare. Foreign body can be ingested accidentally or in a suicidal attempt. However, ingested foreign body causing sigmoid colon perforation is extremely rare. Complications caused by ingestion of foreign body in gastrointestinal tract include obstruction, perforation, bleeding, or impaction at the sites of physiological narrowing or acute angulation in gastrointestinal tract. We hereby report a case of sigmoid colon perforation due to swallowed partial denture.