Large-cell (non-Hodgkin's) lymphoma may occur in the eye as a cellular infiltrate in the vitreous, uveal tract (choroid), retina, or optic nerve. Lymphomatous involvement may be limited to the eye but also is frequently associated with lesions of the central nervous system. Ocular involvement may precede involvement of the central nervous system by months or, in some cases, years. Ocular large-cell lymphoma is bilateral in approximately 80% of cases but often is asymmetric. The mean age of patients with ocular large-cell lymphoma is 60 years, and women are affected almost twice as often as men. Intravitreal large-cell lymphoma may manifest as an infiltrate of large glassy-gray cells or clusters of cells, and it may mimic uveitis or other inflammatory and infectious conditions of the eye. The diagnosis is based on cytologic and immunocytochemical studies of a vitreous biopsy specimen obtained by aspiration or by vitrectomy through the pars plana. Advances in irradiation of the eyes and the central nervous system, supplemented with corticosteroids and intrathecally and intravenously administered chemotherapeutic agents, have resulted in improvement of the dismal prognosis for patients with large-cell lymphoma.