The effect of treatment with SrCl2 (10 mg 100 g-1) on rats 15 min prior to whole body gamma-irradiation (7.5 Gy) was studied. The hazardous effects of irradiation were greatly corrected in the treated group. The hyperglycemic effect and liver glycogen accumulation in the untreated group decreased to normal level. The enzymatic activities of serum alkaline phosphatase, alanine and aspartate aminotransferases, and lactate dehydrogenase were greatly affected, showing insignificant changes in the treated group of animals. Life span calculated on 50% survival was also significantly elongated by 36.3%. These results show the potentiality of SrCl2 as a radioprotective agent. A proposed mechanism is discussed.