Primary oculocerebral non-Hodgkin lymphoma (NHL) of the immunocompetent patient is associated with significant morbidity and mortality, but early diagnosis and follow-up may improve prognosis. The eye, anatomically and embryologically part of the central nervous system (CNS), can be the primary site of the lymphomatous process. In patients with symptoms of atypical uveitis, vitrectomy can be of great help for early diagnosis of primary central nervous system lymphoma. We retrospectively reviewed the diagnostic features, treatment, and evolution of 10 patients with primary central nervous system lymphoma who presented with symptoms of pseudouveitis. The patients complained of chronic vitreal opacities, increasing with time. These symptoms contrasted with the absence of the usual signs of inflammation of the anterior segment or of the retina, which characterize true uveitis. Vitrectomy was proposed after lumbar puncture and cerebral magnetic resonance imaging. Six vitrectomies were carried out, 3 patients had a stereotaxic biopsy, and 1 patient had a cardiac biopsy. A pathologic diagnosis of large B-cell lymphoma was made on vitrectomy specimens in 100% of the patients who had this procedure. The mean time from onset of ocular symptoms to diagnosis was 24 months. This series was characterized by a rare systemic dissemination of the NHL (negative in 80%), a strong preponderance of B-cell NHL, and the absence of association with Epstein-Barr virus (EBV) among these immunocompetent patients. To our knowledge, this series includes the only reported case of oculocardiac lymphoma. Meningeal dissemination appeared to be associated with a poor prognosis. Neurologic complications of treatment combining radiotherapy and methotrexate were significant among patients older than 60 years of age. The current study suggests that primary central nervous system lymphoma should be suspected in patients with pseudouveitis, and that the diagnosis can be established quickly and without side effects by vitrectomy. These patients should be followed carefully in order to detect meningeal dissemination.