Bilateral cavernous sinus syndrome is usually due to a vascular disease, such as thrombophlebitis or arteriovenous malformation. In a 29-year old woman this syndrome revealed a malignant non-Hodgkin's lymphoma of the Burkitt type. In this case, the physiopathological mechanism was metastatic extension to the dura mater of a systemic lymphoma. The contribution of MRI to the diagnosis is emphasized.