Isolated sixth nerve palsies usually occur in the vasculopathic age group and are often associated with diabetes mellitus, hypertension, and atherosclerosis but also occur in the presence of skull base tumors. However, isolated bilateral sixth nerve palsies are an extremely rare complication of skull base lesions due to metastatic neoplasms. A case of a 46-year-old man with metastatic small-cell carcinoma of the lung that developed acute bilateral abducens nerve palsies is presented. Although this appears to be an isolated case, metastasis to the skull base must be included in the differential diagnosis of isolated bilateral sixth nerve palsies. (C) 2003 Elsevier B.V. All rights reserved.