Extramedullary plasmacytoma is a rare plasma cell neoplasm, and it is extremely uncommon in the testicles. We report a 73-year-old man with multiple myeloma presented with testicular plasmacytoma. He complained of left leg pain and scrotal swelling. Ultrasonography revealed testicular masses. Pathologic examination of the orchiectomy specimen showed plasmocytoma with kappa expression. Multiple lytic bone lesions were seen in bone survey scans, serum immunoelectrophoresis and bone marrow aspiration aided to the diagnosis of multiple myeloma. He received chemotherapy, melphalan and prednisolone, and palliative radiotherapy. He succumbed to disease after 8 months.