Sixty-three eligible patients with Ann Arbor clinical Stage II or IIE aggressive histologic type non-Hodgkin's lymphomas received combination chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone [COPA]) as the primary treatment technique. Moderate-dose radiation therapy (2500 to 3000 cGy in 2 to 3 weeks) was given to anatomic areas involved initially by lymphoma in patients demonstrated to be in complete remission after chemotherapy. Fifty-seven percent of the patients were free of lymphoma clinically after induction chemotherapy. The minimum patient follow-up from the start of chemotherapy is 3.7 years, and the median follow-up for patients still alive is 4.7 years. The progression-free survival is projected to be 62% at 4 years, and 86% of the patients achieving a complete response are projected to be in continuous remission at 4 years from the completion of all therapy. There were no treatment-related fatalities. This treatment sequence has produced durable tumor control in the majority of patients with acceptable toxicity. The need for consolidation radiation therapy is being studied currently in a controlled clinical trial.