The activity of the adrenal gland is connected with the activity of other endocrine glands, such as the gonads. The experiments were conducted on testectomized adult, male rats, Wistar strain, acclimated on two ambient temperatures: room and moderately high temperature. Bilateral testectomy was performed on the rats of both temperatures and analyses were made 15-20 days after surgery. It was shown that the adrenal weight of testectomized heat acclimated rats was significantly increased. The widening of zona reticularis, shortening of zona fasciculata, as well as presence of supracortical nodules in the adrenal cortex of testectomized rats, regardless of the ambient temperature, was evidenced. Lipid content in the adrenocortical cells was lowered in both groups, but that was more prominent in testectomized rats from room temperature. The morphometric measurements of the nuclear area and volume were significantly elevated only in zona reticularis cells of testectomised animals from room temperature. Those parameters were significantly decreased in testectomized heat acclimated rats in comparison with the same values in the testectomized animals from room temperature. These results suggest that testectomy provokes changes towards increased activity of the adrenal cortex in both ambient temperatures, but those changes are less intense in heat acclimated animals.