The authors retrospectively reviewed the diagnosis and management of 20 intraocular lymphoma patients who initially presented with either ocular or central nervous system (CNS) disease. As the ophthalmic community has become more aware of this entity, the interval between symptoms and diagnosis has significantly shortened. Diagnosis can usually be made on cytopathologic examination of vitreous cells. However, in three cases more than one vitreous biopsy was necessary. Results of cytologic examination appeared to be more accurate than those of conventional lymphocyte surface marker studies in the diagnosis of an intraocular lymphoma. Long-term survival occurred in some patients treated with a combination of intrathecal chemotherapy and ocular/CNS irradiation.