Bilateral superior ophthalmic vein (SOV) enlargement has rarely been shown to occur in patients with septic and aseptic cavernous sinus thrombosis, Graves' disease due to obstruction of the SOV by enlarged extraocular muscles, or carotid-cavernous fistulas caused by retrograde flow. The authors describe 11 patients with bilateral SOV enlargement associated with cerebral swelling as detected by computerized tomography scanning. The bilaterally enlarged SOVs returned to a normal size following resolution of cerebral swelling and elevated intracranial pressure. To the authors' knowledge, this is the first report of bilateral SOV enlargement associated with diffuse cerebral swelling that subsequently resolved after treatment of the cerebral edema. The authors believe that the bilateral SOV enlargement was caused by mechanical cavernous sinus venous stagnation due to cerebral swelling, a syndrome that occurs more commonly than currently appreciated.