An 11-year-old male Rex rabbit (Oryctolagus cuniculus) had a rectal prolapse induced by a polypoid mass. The mass was highly vascularized with a cauliflower-like appearance. Anorectal papilloma was suspected, and fine needle aspiration cytology showed eosinophilic inflammation. After surgical removal of the polyp, postoperative care was given, such as systemic antibiotics and analgesics. In the re-examination, the rabbit was resolved, and there were no complications. Histopathological examination of the removed polyp indicated chronic eosinophilic proctitis to be the cause of the inflammatory condition of the protruding rectal polyp.