Primary anorectal melanoma is a rare malignant tumour with more than 500 cases reported in the literature and has an extremely poor prognosis. This disease is sometimes mistaken for such benign conditions as haemorrhoids. We report on a 73-year old man with symptoms of rectal pain and bleeding. The diagnosis was established with colonoscopy and biopsy, and radiation and rectal resection were performed. The survival time from when the tumour was diagnosed was two years. Early diagnosis is key for efficient treatment and to improve survival rate for patients with anorectal melanoma.