Data are presented on the effect of the amount of pantothenic acid in the diet of chickens on the level in the blood and tissues. On an adequate intake of pantothenic acid (1575 μg per 100 gm of feed) the average level in whole chicken blood was 43.6 μg per 100 ml and for plasma 51.6 μg. These values are 118 and 147% higher than the respective values for the blood and plasma of chickens on an intake of about 385 μg of pantothenic acid per 100 gm of feed. In whole chicken blood an average of 86.2% of the pantothenic acid occurs in the plasma, which is somewhat higher than the corresponding figure for the blood of mammalia. The amount of pantothenic acid ingested had no significant effect on the amount of pantothenic acid in the liver. On a diet containing approximately 1575 μg of pantothenic acid per 100 gm of feed the average pantothenic acid value for liver was 44.9 μg, for leg muscle 17.2 μg and for breast tissue 11.3 μg per gm of fresh tissue. The level of pantothenic acid in the leg muscle and breast tissue was significantly influenced by the amount ingested. The addition of pantothenic acid to the diet of chickens that had been on a low intake resulted in a relatively rapid deposition of pantothenic acid in the leg muscle and breast tissue so that the amount in these tissues reach the normal level for the amount ingested within a period of 2 to 4 weeks.