Background To investigate the effects of consolidation radiation in patients with stage IE-IIE, non-bulky primary gastric diffuse large B-cell lymphoma (DLBCL). Methods A cohort consisted of 71 consecutive patients with stage IE-IIE, non-bulky primary gastric DLBCL was retrospectively analyzed. All of them had been in complete remission after receiving at least four cycles of chemotherapy, containing rituximab or not. Consolidation radiation was delivered thereafter in 28 patients while other 43 received clinical observation only. Locoregional relapse-free survival (LRFS), disease-free survival (DFS), overall survival (OS) and distant metastasis-free survival (DMFS) were compared between patients with or without radiotherapy. Results The 10-year LRFS, DFS, OS and DMFS were 100% and 81.4%(p = 0.028), 91.7% and 77.1% (p = 0.14), 91.7% and 77.8% (p = 0.67), 91.7% and 78.0%(p = 0.42) for patients with or without radiotherapy. Conclusions Radiotherapy is associated with improved locoregional control of patients with early stage primary gastric DLBCL, who have achieved complete remission following at least four cycles of chemotherapy.