Intraocular lymphoma is a rare ocular malignancy that may occur in the retina or the uvea. Retina or vitreoretinal lymphoma accounts for the majority of cases and is often secondary to diffuse large B-cell lymphoma. In the present study, a 66-year-old Caucasian male with a history of Waldenstrom's macroglobulinemia with diffuse large B-cell lymphoma, presented with blurred vision in the left eye one month following cycle 4 of an R-CHOP regimen. At the time of onset, the patient was being treated for bacterial pneumonia. Visual acuity was 20/25 in his right eye (OD) and 20/30 in the left (OS). Ophthalmologic examination showed intraretinal white infiltrates associated with hemorrhage in the superotemporal midperiphery of the retina and vitritis OS. Initial diagnostic considerations included infectious (cytomegalovirus retinitis, syphilis, toxoplasmosis, tuberculosis), inflammatory (retinal vasculitis associated with autoimmune disease or hypercoagulable states) or malignant (intraocular lymphoma) diseases. The patient did not respond to intravitreal injection of foscarnet and oral valgancyclovir. Systemic work-up and aqueous fluid biopsy were inconclusive. Diagnostic vitrectomy yielded inconclusive results and the patient continued to have progressive loss of vision. A repeat diagnostic vitrectomy with retinal and subretinal biopsy confirmed large B cells consistent with metastatic B-cell lymphoma. A concomitant PET/CT scan was performed that revealed bilateral new pulmonary nodules resulting in additional chemotherapy. Our case shows the diagnostic dilemmas in patients with systemic lymphoma and the possible role of concurrent systemic restaging in patients with ocular complaints, even when in systemic remission.