We experienced a rare case of a pedunculated polyp of the appendix, which had been incidentally found by preventive appendectomy performed when providing surgical treatment for rectal carcinoma. A pathological investigation of this polypoid lesion demonstrated branches of fibro-muscular stalks connecting with the lamina muscularis covered by a hyperplastic mucosa, which proved to be consistent with the features of hamartoma. The patient had no external characteristics of Peutz-Jeghers syndrome, including mucocutaneous pigmentation and gastrointestinal polyposis, observed by endoscopy. This case is considered to be a Peutz-Jeghers type polyp of the appendix with a pedunculated form, which is very rare.