Most bladder tumors are epithelial in origin. Nonepithelial cancers are rarely located in the bladder. Sarcomas are the most common malignancies among nonepithelial cancers. Primary bladder lymphoma is rare and mostly low grade. Here, we have reported a case of diffuse large cell lymphoma of the bladder. The patient, a 64-year-old man, had urinary frequency for 18 months. Abdominal sonography indicated a thick bladder wall and transurethral biopsy showed diffuse large cell lymphoma. Immunohistochemistry (IHC) results showed that the tumor was positive for CD20, CD45, and Pax-5 and negative for BCL-2, cytokeratin, and S100. He had a normal bone marrow biopsy, abdominal, pelvic and chest CT scans. He had no B symptoms. The patient received 6 cycles of R-CHOP followed by radiotherapy (36 Gy) to the pelvis. Six months after treatment, the patient is well and has returned to work. We have searched PubMed for primary diffuse large cell lymphoma. Primary diffuse large cell lymphoma of the bladder is best treated according to treatment for diffuse large cell lymphoma of other sites, which includes chemotherapy and radiotherapy. As seen in our review, primary diffuse large cell lymphoma of the bladder has a similar clinical course to diffuse large cell lymphoma of other sites.