Paragonimus westermani is a lung fluke that is usually found in the lungs, but may be found in unusual locations. A case of omental and mesenteric paragonimiasis was found incidentally during surgical intervention for rectal cancer. A 59-yr-old male patient visited our hospital for low abdominal pain and decreasing stool caliber. He had a history of ingestion of raw freshwater fish and crab. He was diagnosed as having rectal cancer, and a palliative Hartmann's procedure was performed. During the operation, several seeding nodules were found. Microscopic findings showed numerous paragonimus ova in the resected omental and mesentery. We report a case of heterotopic paragonimiasis in the abdominal cavity after rectal cancer surgery.