While metastases to the paranasal sinuses are unusual, metastases to the sphenoid sinus are exceedingly rare, especially metastases of a cutaneous melanoma to the mucosa. We report the case of a 38-year-old man who presented with a solitary sphenoid sinus metastasis that had spread from a cutaneous malignant melanoma. The metastasis was removed via a wide, endoscopically assisted sphenoidotomy. The patient was further treated with external radiotherapy, and at 8 months of follow-up he was free of disease. However, he experienced a recurrence at 3 years that proved to be fatal. We review the pathogenesis and histopathology of sinus metastases, and we discuss the imaging features that characterize melanoma metastatic to the upper respiratory tract. While complete cure of patients with a sphenoid sinus metastasis has not been reported, significant palliation with radiation therapy is possible in many patients. Therefore, patients with sphenoid sinus symptoms suggestive of a sphenoid sinus malignancy should be vigorously evaluated for the possibility of a primary malignancy as well as a metastasis to the sinus.