The 10 year results of a trial of bimodal treatment of Hodgkin's disease in children with 6 cycles of MOPP and low-dose extended field irradiation, without staging laparotomy, were for 57 children in all stages as follows: survival 85%, relapse-free survival 80%, and survival-free of second relapse 86%. There were three fatal toxic events, two due to viral infection and one to a second malignant tumor (NHL). Three other patients developed a second malignant tumour, and one developed a thyroid adenoma. No patient developed acute leukemia. These results are compared with the results of treatment of surgically staged children by extended field irradiation alone, with bimodal treatment reserved for relapse or advanced disease at diagnosis. Initial bimodal treatment improved the overall 10 year survival free from a second relapse rate by 20% (86% vs. 66%). No major difference in treatment toxicity between these two groups has emerged during the first 10 years of follow-up. We conclude that, except for favourable CS-1 presentations, children with Hodgkin's disease confined to the lymphatic system should be given bimodal treatment, but that the least morbid effective combination remains to be determined.