The preseni experiment was made to determinate the changes in the cyanide and thiocyanate levels in blood, urine and (issues. In this study, 400 mice their body weights from 40 to 45g were used. Sodium cyanide were mtrapentonally given in doses ol 0.1. 0 2, 0.4, 0.8 and 1 4 mçykg. Blood samples were obtained with decapitation of mice. Tissue samples ware taken Irom mice killed with chloroform. The cyanide and thiocyanate levels in samples were colorimelrically established oxidation of cyanide and thiocyanate by bromine water and coupling of pyridine -benzidine reagent. Sodium cyanide increased the cyanide and thiocyanate levels in blood, urine, liver, spleen, kidney and muscle samples in given all doses. The cyanide and thicyanale levels in blood, tissue and urine started lo increase respectively at 6min.. 1h. and 4h. and reached the maximum levels according lo doses at the different times. Then the cyanide and thiocyanate levels in samples gradually decreased and the cyanicfe levels in blood reduced the near levels of control groups at 720min. The thiocyanate levels in blood, the cyanide and thiocyanate levels in liver, spleen, kidney and muscles decreased the near levels ol control groups at 96h.