PURPOSE The study was undertaken to evaluate the long-term results in a favorable subset of patients with pathological Stage IA-IIA treated with irradiation alone. METHODS AND MATERIALS One hundred and forty-seven adults with laparotomy- Staged IA-IIA "favorable" Hodgkin's disease were treated with primary subtotal nodal irradiation. Patients with infradiaphragmatic presentation were irradiated through paraortic and inguino-iliac node chains (inverted Y field) followed by prophylactic mediastinal and supraclavicular fields. RESULTS Actuarial overall survival (OS) at 7 years (median follow-up 77 months) was: 93% for the whole series, 94% for Stage I, and 92% for Stage II. The freedom from first progression (FFP) (80% for the whole series) showed a statistically significant difference (p = 0.008) between Stage I (88%) and Stage II (71%). By univariate analysis, stage alone had an independent prognostic significance for OS and FFP. Of the 29 relapsed patients, 8 were previously classified as Stage I and 21 as Stage II; 16 of 29 (55%) of the relapses occurred in the pelvis and 9 in extranodal sites. After salvage treatment with chemotherapy all patients achieved a second complete remission. Seven second malignancies (two acute nonlymphocytic leukemias, one preleukemic syndrome, and four solid tumors) have been detected so far. Hypothyroidism was observed in 16% of patients and a reversible pulmonary restrictive syndrome in 14% of cases, respectively. CONCLUSIONS Within 7 years from radiation therapy, about one-quarter of the patients with Stage II disease will experience a relapse and need intensive salvage chemotherapy. This is not invariably successful and safe, for it may be complicated by either acute or potentially fatal long-term adverse effects, such as second malignancies and cardiac or pulmonary sequelae, in about 5% of patients. The high frequency of relapse in Stage IIA patients suggests a combined modality approach with relatively short-term chemotherapy not including alkylating agents.