A 44-year-old man with Wegener's granulomatosis involving the upper and lower respiratory tracts developed a diplopia with involvement of three extraocular muscles of one eye and one extraocular muscle of the other eye. The ocular and orbital examinations were otherwise normal, as were computerized tomography (CT) scans of the brain and orbits. The patient was treated with systemic Cytoxan and Prednisone and the respiratory and extraocular muscle abnormalities cleared within 1 month. Because of the bilateral extraocular muscle involvement, the absence of central nervous system or orbital findings, and the rapid and complete resolution after Cytoxan and Prednisone therapy, a diffuse vasculitis affecting the extraocular muscles was implicated as the etiology of the diplopia.