1) Taurine-35S was injected intravenously to rats and the radioactivity in tissues, bile, urine and feces was measured at various time intervals after the administration. 2) Taurine-35S was rapidly eliminated from the blood stream almost regardless of its dosage levels examined. The largest accumulation of radioactivity in the earlier periods was found in the kidney, liver and small intestine. The spleen and lung followed them. The least uptake of 35S was observed with the brain. 3) The radioactivity in the heart, diaphragm and muscle increased gradually, whereas that in the other organs decreased. 4) As for the intracellular localization, radioactivity was present in the soluble fraction of all the tissue homogenates tested. 5) 35S readily appeared in the bile, wherein free taurine-35S as well as its conjugates with bile acids was recognized. 6) A large, initial uptake of 35S by the intestinal walls was found to be essentially independent of the reabsorption of radioactive biliary components. 7) No particular accumulation of taurine-35S was noticed in a newly formed granuloma tissue within the limits of the present study.