A 40-year-old female visited our clinic for visual disturbance of the right eye, in which a few creamy-yellow retinal lesions and visual field constrictions were noted. She had been treated for primary CNS lymphoma and was in complete remission. After failure to follow-up for three months, she lost vision in the right eye, at which time active panuveitis was seen. Decreased vision and field constriction was observed in the left eye. Her left eye showed a granular pattern and dye leakage from the vessels and disc on fluorescein angiography and small RPE humps were seen in optical coherence tomography (OCT). Diffuse large malignant B-cells with strong immunoreactivities with CD20 immunostaining were seen in the epiretinal membrane biopsy specimen. Intravitreal injections of methotrexate (MTX) (800 µg/0.1 ml in the right eye, 400 µg/0.05 ml in the left eye) were performed twice weekly for one month, once weekly for the following month, once every two weeks for the next month, followed by nine monthly injections. Both eyes were free from malignant cells on vitreous biopsy six months later. There was no leakage seen by angiography, but the granular pattern persisted. Visual field constriction was slightly improved, and the small RPE humpsdetachments seen in OCT disappeared. EOG Arden ratio was decreased in both eyes, and b wave amplitude of scotopic ERG was decreased in the left eye. She was free from recurrence until six months later. No ocular complications except minimal opacity of the crystalline lenses were noted in both eyes.