Objective To investigate the clinical features, diagnosis, treatment and prognosis of primary testicular diffuse large B-cell lymphoma (PT-DLBCL). Methods The clinical data of 2 patients with PT-DLBCL in the Second People's Hospital of Lianyungang treated in May 2013 and April 2018 was retrospectively analyzed. The clinical features, diagnosis, treatment and prognosis of PT-DLBCL were summarized with review of these 2 cases combining with other 42 cases reported in domestic literature. Results Case 1, a 71 years old man, complained of bilateral scrotal enlargement with pain and discomfort for 2 months. Case 2, an 85 years old man, presented with left scrotal mass for 3 months. All 2 patients underwent orchiectomy. Both of the 2 patients were diagnosed as PT-DLBCL and non-germinal center B-cell (non-GCB) subtype and had Ann Arbor stage ⅠE after operation. Case 1 received only 2 cycles of CHOP (cyclophosphamide, epirubicin, vincristine, prednisone) due to lack of financial support. Case 2 refused chemotherapy and right testis irradiation because of advanced age. They were followed up for 71 months and 12 months, respectively. They were both alive without recurrence at last time of the follow-up. The median age of 44 patients (2 cases in this study and 42 cases reported in the domestic literature) was 64 years old (range 45-87 years old). The most common symptom was unilateral painless testicular swelling (left testis 17 cases and right testis 24 cases). Twenty-one patients were Ann Arbor stage Ⅰ, 6 patients were stage Ⅱ, 6 patients were stage Ⅲ, and 11 patients were stage Ⅳ. Thirty-one patients were non-GCB subtype. Twelve patients were international prognostic index (IPI) score ≥3. Serum lactate dehydrogenase (LDH) level was elevated in 13 patients. All patients underwent orchiectomy. CHOP/R-CHOP chemotherapy was given to 40 patients and prophylactic radiation to contralateral testis was given to 12 patients. Twenty-two patients received prophylactic intrathecal chemotherapy. After a median follow-up of 17 months (range 3-135 months), 14 patients died and the median overall survival time was 13 months (range 3-96 months). Conclusions PT-DLBCL is rare. Its diagnosis mainly depends on pathology, with the majority of patients diagnosed in early Ann Arbor clinical stage and non-GCB subtype. The radical orchiectomy and R-CHOP chemotherapy is recommended due to local relapse and systemic dissemination. It is curable in the early stage while patients with advanced stage have a very poor prognosis. Prophylactic radiation to contralateral testis and intrathecal chemotherapy can decrease the risk of recurrence. Key words: Testicular neoplasms; Lymphoma, large B-cell, diffuse; Diagnosis; Treatment; Prognosis