SummaryStudy of the urinary excretion of P32injected intravenously in several types of diseases has given the following results :1°Leukemic patients generally excrete about 13 % of the injected amount in 3 days and 20 % in 6 days.2°Patients with lymphosarcoma excrete 13,5 % in 3 days and 21,5 % in six. Retention is more marked in generalised forms.3°In patients with Hodgkin’s disease excretion is 31 % at the 3dday and 41,7 % at the 6thday. Retention is the highest in generalised forms of the disease.4°Treatment of lymphosarcoma and of Hodgkin’s disease with P32does not give the favourable results observed in leukemia and polycythemia.