Objective To investigate the impacts of adjuvant radiotherapy on the prognosis of patients with stage Ⅰ-Ⅱ diffuse large B cell lymphoma of Waldeyer’s ring (WR-DLBCL) who achieved complete remission (CR) after chemotherapy. Methods Clinical data were collected from 130 patients with stage Ⅰ-Ⅱ WR-DLBCL who were admitted to our hospital from 2005 and 2013. All the patients achieved CR after at least two cycles of cyclophosphamide, doxorubicin/epirubicin, vincristine, and prednisone (CHOP)-based chemotherapy or rituximab plus CHOP (R-CHOP)-based chemotherapy. In the 130 patients, 43 received R-CHOP (including 25 patients undergoing radiotherapy) and 87 CHOP (including 76 patients undergoing radiotherapy); 29 received chemotherapy alone and 101 chemoradiotherapy. The survival rates were calculated by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate prognostic analyses were made by the log-rank test and the Cox model, respectively. Results In all patients, the 5-year sample size was 101. The univariate analysis showed that patients with an Eastern Cooperative Oncology Group (ECOG) score of 0 had significantly higher 5-year overall survival (OS) and disease-free survival (DFS) rates than those with an ECOG score of 1(95.6% vs. 80.1%, P=0.000; 95.7% vs. 75.4%, P=0.029). Patients treated with chemotherapy alone had significantly lower 5-year OS and DFS rates than those treated with chemoradiotherapy (77.1% vs. 91.7%, P=0.048; 77% vs. 87.4%, P=0.037). The multivariate analysis by the Cox model showed that ECOG score was a prognostic factor for both OS and DFS (P=0.047, 0.003). Adjuvant radiotherapy was related to improved DFS rather than OS (P=0.039, 0.133). Conclusions Stage Ⅰ-Ⅱ WR-DLBCL patients with low ECOG scores have better prognosis than those with high ECOG scores. Patients with CR after chemotherapy may benefit from adjuvant radiotherapy. The conclusions need to be further confirmed by prospective randomized controlled trials. Key words: Diffuse large B cell lymphoma/chemotherapy; Diffuse large B cell lymphoma/radiotherapy; Prognosis