Between 1976 and 1981, 63 patients with Stage II-IV testicular non-seminoma were treated by chemotherapy followed 4-6 weeks later by involved field radiotherapy. Of this group, 58 (92.1%) are alive and tumour-free, one patient died post-operatively and four of uncontrolled disease. There were no deaths from drug-induced neutropenic sepsis. During the same period a second group of 53 patients who had received radiotherapy were given chemotherapy for recurrent disease. Of this group, 38 (71.7%) are alive and tumour-free, eight died of uncontrolled malignancy, six from drug-related complications and one from a myocardial infarct. In patients receiving elective post-chemotherapy irradiation, tumour volume exerted little influence on treatment outcome, the disease-free survival rates for small volume and bulky disease being 100% and 87.2%, respectively. Conversely, in patients receiving chemotherapy after prior irradiation there was a significant difference; 96.7% and 43.4%, respectively (p less than 0.001). Of the 63 patients in the drug-irradiation protocol group 23 (36.5%) had residual masses excised. In 18 patients (78.2%) the excised tissue showed either fibrosis or mature teratoma. Despite the excellent survival figures for patients receiving post-chemotherapy irradiation the value of this approach cannot be assumed, although the slight difference between small and bulky presentations suggests that radiotherapy may have contributed to the therapeutic result.