['The role of rituximab in combination with CHOP regimen in patients with stage I diffuse large B-cell lymphoma (DLBCL) remains to be defined. We aimed to compare CHOP plus rituximab (R-CHOP) with CHOP alone and determine the value of radiotherapy in these patients.', 'Between 2003 and 2009, 140 untreated patients with stage I DLBCL were retrospectively analyzed in this study.', 'Seventy-eight patients were treated in R-CHOP group and 62 in CHOP group. Ninety-one patients received additional radiotherapy at the end of chemotherapy. The different treatment groups were well-balanced with respect to baseline characteristics. Complete response (CR) rate was 77% both in R-CHOP and CHOP groups (P=0.945). After a median follow-up period of 56 months, patients received R-CHOP regimen had similar 5-year progression-free survival (PFS) (76% vs. 85%; log-rank P=0.215) and 5-year overall survival (OS) (90% vs. 96%; log-rank P=0.175) compared with those with CHOP alone. Patients with radiotherapy had significantly increased 5-year PFS compared with those who had chemotherapy alone (86% vs. 71%; log-rank P=0.005). At multivariate analysis, patients who had CR (P=0.008) and received radiotherapy (P=0.003) were significantly associated with superior PFS.'] Is addition of rituximab associated with survival benefit compared with CHOP alone for patients with stage I diffuse large B-cell lymphoma?