Objective To investigate the clinical characteristics and prognostic factors of diffuse large B-cell lymphoma (DLBCL) in the elderly. Methods A total of 50 DLBCL patients (≥70 years old) admitted in our department from Jan. 2010 to Jan. 2013 were enrolled in this study. Clinical data including age, Ann-Arbor stage, B symptoms, international prognostic index (IPI), serum levels of lactic dehydrogenase (LDH), β2-microglobulin (β2-MG) and Ki-67, and other indices were collected and retrospectively analyzed. Survival analysis was performed by Kaplan-Meier survival analysis (the Log-rank test), and the correlation of these indices with prognosis was performed by univariate analysis. Results Among the 50 elderly with initial DLBCL, 60% were at Ann-Arbor stage of Ⅲ?Ⅳ, 54% got IPI score of 3?5 points, 52% had B symptoms, and 75% were with extranodal as primary site of the disease. In the cohort, the therapeutic effect was better in the patients given dose-adjusted chemotherapy than those receiving radiotherapy and supportive therapy. Moreover, the complete remission (CR) rate was higher in the patients getting R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine and prednison) than those of CHOP/COP regimens. The median survival time was 8 months, and the 1-, 2-, 3-year overall survival rate (OS) was 48.5%, 30.8% and 11.5%, respectively. Survival analysis showed Ki-67 had great effect on prognosis, and those with Ki-67 ＞80% had poor outcome. Conclusion Elderly patients are characterized by being at late stage of disease, with various combined diseases, and having short survival time, and have a high incidence of DLBCL. Ki-67 is regarded as an important factor for poor prognosis. The R-CHOP scheme greatly improves CR rate, and adequate chemotherapy is important to prolong survival time in the elderly DLBCL patients.