[en] Purpose/Objective: To evaluate whether or not a total dose (TD) of 30 Gy is sufficient for treatment of assumed subclinical Hodgkin's Disease compared to 40 Gy TD with early stage Hodgkin's Disease (ESHD). Materials and Methods: In a prospective multicenter trial, 376 patients with laparotomy proven ESHD stages PS IA to PS IIB without risk factors such as large mediastinum, extranodal involvement or 3 and more involved lymphnode areas were randomly allocated either to receive (A) 40 Gy TD extended field-radiotherapy (EF-RT) or (B) 30 Gy TD EF-RT plus 10 Gy TD involved field-radiotherapy (IF-RT), both arms without any chemotherapy. 366 of these patients were evaluable for early and long-term response, such as remission status, freedom from treatment failure (FFTF), and overall survival (OAS). For quality control, all planning and verification films as well as dose charts were prospectively reviewed by a panel of four experts, all head of a radiotherapy department, where protocol violations (PV) were seen either with regard to errors in treatment volume and/or in time/dose-relationship. Results: Treatment resulted in a complete remission (CR) of 98%, in a 5 years' FFTF of 76%, and a 5 years' OAS of 97%. There was no difference between the two arms in favour of 40 Gy EF compared to 30 Gy EF regarding FFTF and OAS, without any in field-relapse throughout the EF-volumes. Expectedly, 5 years FFTF was significantly influenced by the quality of radiotherapeutical procedures: 70% with protocol violations vs 80% without PV. Conclusion: Subclinical involvement in ESHD without risk factors is sufficiently treated by a TD of 30 Gy without chemotherapy, leading to a 5 years' FFTF of 80% and a 5 years' OAS of 97% in a multicenter treatment setting, where quality assurance is mandatory