Anorectal malignant melanoma is a rare tumor and there is no consensus on whether aggressive or local management is more appropriate. Local sphincter-saving excision has been shown to have a higher recurrence rate than abdominoperineal resection, although there is no long-term survival difference between the two approaches. Therefore, new adjuvant treatment strategies to permit local sphincter-saving excisions are warranted. In our case, a large anorectal malignant melanoma was successfully treated preoperatively by electrochemotherapy with cisplatin that, by reducing the tumor size, enabled sphincter-saving local excision. Brachytherapy was postoperatively delivered to the excision site. Fourteen months after the beginning of treatment, the patient is without signs of local recurrence and is continent.