Primary involvement of the bladder and prostate by non-Hodgkin lymphoma is exceedingly rare. Usually bladder lymphoma can be cured by aggressive local therapy, but the prognosis of prostatic lymphoma is poor. The devastating clinical course of a young man with primary lymphoma involving the prostate and bladder base is reported to emphasize the heterogeneity of this group of tumors and to encourage precise tumor classification. Prognosis depends on the tumor stage and the specific lymphoma cell-type as defined by conventional histologic and immunologic criteria. Management should be tailored according to tumor grade, stage, and site.