Primary intraocular lymphoma (PIOL) is a subset of primary central nervous system lymphoma. The incidence of PIOL has increased in the past 20 years. PIOL often presents as chronic uveitis that is resistant to corticosteroid therapy. Diagnosing PIOL can be challenging and requires an expert pathologist. The treatment of PIOL is difficult because of its high recurrence rate and refractory nature. The objective for the future is to improve diagnostic techniques and therapeutic success while minimizing ocular toxicities.