On the bases of previous experiences and present results it can be stated that total-body irradiation is an effective therapeutical technique for treatment of lymphocytic non-Hodkin's lymphomas including chronic lymphatic leukemia; first results from prospectively randomized studies even revealed a slight superiority of this method as compared to the scheme of combined cytostatical therapy (CVP) mostly applied at present. Particular advantages of total-body irradiation are the easy applicability, the relatively short time needed for treatment, and the lack of subjective secondary effects. Thus, ambulatory therapy can be performed without any difficulty. The only complication which may occur arises from myelotoxicity reaching its maximum not earlier than after the end of treatment. Careful follow-up of the patients, therefore, is indispensable. The indication of total-body irradiation for the treatment of non-Hodgkin's lymphomas depends on the objective findings, the stage of disease, and mainly on the histological classification.