To describe the demographics, clinical characteristics, and treatment outcomes in patients with primary CNS lymphoma (PCNSL) with ocular involvement. A retrospective chart review was conducted on 61 patients who were diagnosed with PCNSL from January 2000 to October 2008 at the Asan Medical Center, Seoul, Korea. Among 46 patients who underwent ophthalmologic examination, 13 (28%) showed intraocular involvement. Mean age at diagnosis was 52.8 years, and 54% of patients were female. Diagnosis of PCNSL was made by vitrectomy (1 patient) or brain biopsy and/or CSF cytology (12 patients). In 4 (31%) patients, ocular symptoms preceded CNS symptoms. The most common ocular symptom was decreased visual acuity. Nine patients showed bilateral involvement. Intraocular findings included retinal infiltrative lesions (3 eyes), vitritis/vitreous opacity (5 eyes), or both (14 eyes). In addition to systemic chemotherapy and/or radiotherapy, vitrectomy and/or intravitreal methotrexate was utilized in 8 patients. Mean survival duration was 32.2 months (range 2-120 months). Although rare, the number of patients with PCNSL seems to be increasing in Korea. Early detection and dedicated treatment of intraocular lymphoma may result in improved visual outcome.