Abstract: Objective: To discuss the clinical characteristics, pathological features and treatment and prognosis of the primary malignant lymphoma of the prostate. Methods: Clinical data of 29 patients with primary maligmant lymphoma of the prostate were reviewed retrospectively. The median age of the patients was 66 years and the present symptom was lower urinary tract obstruction. The prostate was enlarged in varying degrees. Pathologic diagnosis of all cases revealed the B- cell- sourced non- Hodgkin's lymphoma, with a majority of a diffuse large- B cell lymphoma. The therapeutic modalities included prostatectomy, radiotherapy and chemotherapy. Results: Extraprostatic involvement at various sites occurred in 19 of the 29 patients after diagnosis. Ten patients died of lymphoma, with a median survival of 23 months (ranging from 2 to 30 months) and, 7 still were alive up to 60 months after the diagnosis.Conclusion: Primary malignant lymphoma of the prostate is rare with a poor prognosis. Prognosis has no correlation with the patients' age, but has an association with histological types, tumor clinical stage and treatment methods. Chemotherapy is still a major therapeutic means now.