The level and distribution of 3H-corticosterone (3H-B) was investigated in adult male Sprague-Dawley rats in response to diethyl ether stress, epinephrine (EP) and/or dexamethasone (DXM) administration. Diethyl ether stress caused a significant increase in the 3H-B counts by some of the body tissues and brain regions studied. Plasma 3H-B counts in the stressed rats were found to be twice as much as in the control animals. When EP (1.0 mg/kg) was injected, the tissue-plasma ratios(TPR) of 3H-B were significantly lower (P less than 0.05) than those of the dexamethasone (1.0 mg/kg) treated animals or the control group. The high 3H-B count in the plasma in response to diethyl ether stress or EP may indicate a decline in rate of corticosterone metabolism.