Male guinea pigs fed a vitamin C-deficient diet for 3 weeks had lower concentrations of cholesteryl esters in their adrenals than did control animals fed the recommended intake of the vitamin. Not all esters were affected to the same degree, and the fatty acid profiles of the esters from control and deficient guinea pigs differed; there was proportionately more palmitic and linoleic acids and less docosatetraenoic acid [22:4 (n-6)] in the deficient guinea pig adrenal esters. [Fatty acids are designated as X:Y (n-Z), where X and Y are the numbers of carbon atoms and olefinic bonds in the acid and Z is the number of carbon atoms after the terminal olefinic bond.] A 100-fold excess of vitamin C in the diet also resulted in lower concentrations of adrenal cholesteryl esters than did the control diet, but they were not as low as in the deficient animals. Fatty acid profiles were similar for esters from control and excessively supplemented guinea pigs. Vitamin C deficiency apparently imposes a long term stress which results in a depletion of adrenal cholesteryl esters, possibly specific esters, to meet the requirements for glucocorticoid synthesis.