Four patients exhibiting signs of partial aberrant oculomotor regeneration without a preceding acute third nerve palsy had meningiomas involving the cavernous sinus. Two of the patients had preceding sixth nerve palsies. We propose that slowly progressive primary aberrant oculomotor regeneration is diagnostic of intracavernous meningioma. The best diagnostic studies are orbital phlebography, carotid arteriography, and possibly computerized axial tomography.