Superior ophthalmic vein thrombosis is a rare entity. It is associated with significant morbidities. It may present with dramatic clinical signs. It is frequently secondary to cavernous sinus pathology and it can be a harbinger of cavernous sinus thrombosis. We report an unusual case of superior ophthalmic vein thrombosis, as the first manifestation of multiple myeloma. As far as we know, this is the first case described in the literature. Here we describe a patient presented with a painful, visual blur and a right-sided proptosis due to superior ophthalmic vein thrombosis. Appropriate medical workup was conducted, and smoldering multiple myeloma was diagnosed as the underlying cause. We further discuss the possible involved mechanisms.