Primary extranodal lymphomas (ENLs) are lymphomas with no or minor nodal involvement and a dominant extranodal component originating from any organ. Primary ENL originating in the genitourinary tract is extremely rare. Diffuse large B-cell lymphoma (DLBCL) is the most frequent histological subtype in primary genitourinary lymphoma. Lymphomatous involvement of genitourinary system organs is common in the setting of disseminated disease. Herein, we present a unique case of primary multicentric extranodal DLBCL of the urogenital system involving ureter, seminal vesicle, and penis detected on 18fluro-deoxyglucose positron emission tomography with computed tomography, and to the best of our knowledge, it is the first case report with multiorgan involvement within a single (urogenital) organ system in a patient without disseminated disease, i.e., with no other nodal or extranodal organ system involvement.