For the majority of patients presenting with early Hodgkin's disease, the chance of death due to their disease is related to prognostic factors, e.g. age, systemic symptoms, ESR bulk, number of sites of disease, histology, haemoglobin, lymphocyte count etc. More than 50% of those with Stage I and IIA disease fall into an intermediate prognostic category where a variety of initial treatment strategies--chemotherapy alone (CT), radiotherapy alone (RT) or a combination of chemotherapy and radiotherapy (combined modality therapy CMT) result in comparable survival rates. There is therefore increasing emphasis on incidence of relapse and treatment related morbidities rather than on survival alone when evaluating the role of different treatment for Hodgkin's disease. Radiotherapy has an essential part to play in any initial strategy aiming to keep relapse rate low, as chemotherapy alone has been demonstrated to be less effective in treating macroscopic disease. Late side-effects associated with radiation are largely associated with obsolete techniques involving very wide fields, high doses and large fraction size delivered to anterior structures within the thorax. The risk of second solid tumour appears related to the volume of radiation fields and the risk of cardiac damage is probably related to both total dose and dose per fraction delivered. There is still uncertainty as to the potential late toxicity of modern techniques, particularly in combination with chemotherapy. Increasingly numbers of patients are likely to be treated with initial CMT rather than RT alone to reduce relapse rates. The risk of leukaemia associated with CMT to patients with curable Hodgkin's disease appears to have been overestimated.(ABSTRACT TRUNCATED AT 250 WORDS)