Antrochoanal polyp, a benign solitary polypoid lesion, arises from maxlliary antrum and passes through the ostium of sinus into the nasopharynx. Angiomatous change and autoamputation of antrochoanal polyp is very rare. The author recently experienced a case of autoamputated angiomatous antrochoanal polyp which was expectorated per mouth. The remnant angiomatous antrochoanal polyp was completely removed with endoscopic sinus surgery.