Colloidal zirconyl phosphate P 32, used as a preferred initial and long-term therapy, has given prolonged survival in 179 patients with chronic leukemia and lymphoma. A median survival time of 93.6 months from apparent onset of disease was obtained in 97 patients with chronic lymphocytic leukemia. For chronic myelogenous leukemia, lymphosarcoma, and Hodgkins disease, corresponding survival figures were 49.8 months, 59 months, and 25.7 months, respectively. The digital computer was used to calculate survival times. Radiocolloid zirconyl phosphate is recommended for therapeutic effectiveness related to the concentration of irradiation at the sites of leukemic and lymphomatous infiltrations.