Sinonasal melanoma is a rare disease with limited data regarding its optimal treatment. It is an aggressive disease with up to 60% of patients developing local recurrence or distant metastases in the first 24 months after treatment. We report a case of sinonasal melanoma involving the skull base which was treated by endoscopic anterior craniofacial resection together with brachytherapy postoperatively. The patient has been followed up regularly and at 89 months there is no sign of local recurrence or distant metastases. The use of postoperative brachytherapy to achieve local control has not been reported in the management of sinonasal melanoma.