We describe a patient with bilateral orbital myositis, multiple cranial neuropathies, a sensory polyneuropathy, serum and cerebrospinal fluid paraproteins, and high-grade non-Hodgkin's lymphoma. Neurologic symptoms began more than 1 year before diagnosis of the lymphoma. Results of extraocular muscle biopsy showed extensive destruction of myofibers and granulomatous features, with no evidence of direct tumor involvement. The cranial neuropathies and orbital myositis improved with immunosuppressive therapy, while the patient's tumor progressed. We believe the orbital myositis and the multiple neurologic abnormalities were paraneoplastic effects of the lymphoma. To our knowledge, this is the first case of orbital myositis identified as a paraneoplastic syndrome.