Primary penile lymphoma is rarely observed in cases of extranodal malignant lymphoma. Owing principally to its rarity, no definite treatment modality has been established. We report the case of a 42-year-old man who presented with hematuria and a painless palpable mass on the penis which had persisted for 2 months. A 1.5 × 1.4 cm round mass was detected in the shaft of the penis. Histopathological examination of the excisional biopsy revealed CD20+ diffuse large B cell lymphoma. The patient was classified as having a stage IAE lymphoma. Because radiation often causes considerable early morbidity and later loss of function of the penis, 6 cycles of combination chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisolone) with rituximab were administered at 3-week intervals. After treatment, the patient showed a complete response and has maintained this status for the past 7 months. Multiple options, such as surgical amputation, radiotherapy and chemotherapy, are available for treatment of this condition. However, in order to minimize treatment-related morbidity and to maintain quality of life after treatment, combination chemotherapy including rituximab could be considered the treatment of choice after local excision.