The aim of this study was to investigate whether vitamin C influences the stress response system of the adrenal gland. Adrenalectomized (ADX) rats and non-ADX rats were administered vitamin C and were subjected to electroshock stress (ES) for 5 days. After loading the final stress, stress-related behaviors and corticosterone (CORT), vitamin C, and adrenocorticotropin-releasing hormone (ACTH) levels in the blood were measured. Vitamin C supplementation decreased CORT levels in non-ADX rats. Stress decreased the mean value of rearing frequency in both non-ADX and ADX rats, while vitamin C partially enhanced it only in non-ADX. Vitamin C supplementation decreased mean ACTH level in both groups. It also significantly decreased freezing time increased by stress. Lastly, vitamin C motivated both groups to cross over an electric field more frequently as compared to their respective control groups. These results suggest that the alleviating effect of vitamin C on stress-related rearing behavior was exerted via modulation of CORT, but its effect on freezing behavior may be attributed to corticotropin-releasing hormone (CRH) or ACTH.