Strabismus caused by melanoma metastatic to an extraocular muscle. Nonocular melanoma rarely metastasizes to the orbit. We report the case of a melanoma presumably arising from an axillary lymph node sinus that metastasized to the left medial rectus muscle causing proptosis, diplopia, and reduced saccadic velocity measurements. Clinical, radiographic, and histopathologic data are presented and discussed. 