We present a case of brown tumor of the sphenoid sinus in a patient with secondary hyperparathyroidism. CT showed an expansile soft-tissue attenuation mass centered in the sphenoid sinus. CT at bone window setting demonstrated expansile, lytic change and remodeling of the surrounding bone. On MR imaging, the lesion showed iso-intensity to gray matter on T1-weighted images and heterogeneous hyperintensity on T2-weighted images, and showed intense enhancement. The extent of the lesion and its relationship to the surrounding structures were best evaluated by CT and MR imaging.