A 14-yr-old male, prehensile-tailed porcupine (Coendou prehensilis) presented for an ulcerated, bleeding lesion of the right flank. The wound presented similar to a bite wound and was treated with antibiotics. After 2 mo, the lesion had increased in size and was nonhealing, so surgical excision was elected. Histopathology diagnosed this lesion as a malignant melanoma with incomplete margins. Radiographs showed no evidence of pulmonary metastasis. At 6 mo, another skin lesion was removed and was diagnosed as malignant melanoma with clean surgical margins. At 8 mo, another four dermal masses were surgically excised and, again, these were melanomas that were completely excised. The animal was euthanized approximately 15 mo after initial presentation due to continued growth of dermal masses, dyspnea, and decreased appetite. Necropsy and histopathology revealed metastatic melanoma present in skin, kidneys, and lung.