A 52-year-old woman with suspected primary intraocular lymphoma underwent a diagnostic vitrectomy on her right eye, and the vitreous specimen showed CD20-positive diffuse large B-cell lymphoma. Magnetic resonance imaging showed brain involvement. She underwent whole-brain radiotherapy at a dose of 40 Gy, with 30 Gy administered to the orbit, and systemic high-dose methotrexate therapy. After these therapies, a vitreous specimen from her left eye showed no malignant cells in May 2005. The vitreous opacity in the fellow eye resolved, and the brain involvement responded to therapy. Since then, she has experienced 3 ocular recurrences (May and November 2006 and August 2007) in her right eye, with cells in the anterior chamber and vitreous cavity. Brain magnetic resonance imaging did not show recurrent CNS lymphoma at each time point, and the patient did not want to undergo systemic treatment. Intravitreous methotrexate injections4were administered but were discontinued because of the development of severe corneal epitheliopathy (8 injections for the first recurrence, 6 injections for the second recurrence, and 4 injections for the last recurrence). At the first 2 recurrences, her right eye was free of malignant cells, but at the last recurrence, malignant cells were present and significantly increased in October 2007 (Figure 1A). We then administered an intravitreous injection of rituximab (1 mg/0.1 mL). One week after the first injection, the malignant cells dramatically disappeared from the eye (Figure 1B). The patient subsequently received an intravitreous injection of rituximab weekly for 4 weeks. Except for anterior chamber inflammation, which subsided with topical corticosteroid treatment, no complications developed during and up to 2 months after treatment.