In this study we analyzed our cases of localized aggressive lymphoma treated in our institution during the last 20 years to compare the finding of this study with those of previous studies. Forty patients with Ann Arbor stage I-II aggressive lymphoma were treated with 3-6 cycles of a CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and radiation therapy (30 or 40 Gy with involved field). Between 1985 and 2003, 40 patients with stage I (N = 25) or stage II (N = 15) disease were treated. Chemotherapy mainly preceded radiotherapy, although the sequence of radiotherapy and chemotherapy was determined by individual physicians and patients' choice. Median and mean age was 50.5 and 48.6 years, respectively, at the time of diagnosis, with a male to female ratio of 19:21. Analyses were undertaken to determine (1) response to treatment according to age, international prognostic index (IPI), lactate dehydrogenase (LDH) value, serum interleukin 2 receptor (sIL-2R) value, cell type, stage, extent of maximum local disease, with or without mediastinal lymph nodes, number of sites, anatomic distribution, and irradiation dose, and (2) relapse patterns. Complete follow-up was obtained in all patients. The follow-up period of surviving 33 patients ranged from 24.7 to 180 months with a median of 69 and a mean of 72.7 months. A complete remission (CR) was achieved in 37 patients (93%). A study of relapse patterns after a CR showed that four patients had a first relapse within a radiation field and the other one patient had an extranodal distant relapse. Significant prognostic factors were not identified by multivariate analysis. Combined chemotherapy and radiation therapy is safe, highly effective, and probably curative for most patients with stage I-II aggressive lymphoma.