The results of measurements on an Alderson phantom, as well as in-vivo-measurements, on five patients during total body irradiation are described. They were compared with computer-predicted values using the lateral A.P./P.A. irradiation, as used in Tübingen; measurements were carried out by a TLD method. Particular attention was paid to the critical areas such as the head, the neck and the lungs. The results in general agreed to within 5% and were in good accord with international findings.