Experiments were conducted to study the influence of adrenalectomy, with minimal replacement therapy, on mating behavior and embryonic mortality in thermally stressed mature ewes. Group I ewes were adrenalectomized and maintained post-operatively with 20 mg hydrocortisone and 5 mg deoxycorticosterone daily, with Group II ewes being intact. All ewes were mated and immediately placed in a 32.2 C temperature controlled room for 5 days. They were then removed, slaughtered, and the reproductive organs and intact adrenals collected.Reproductive performance was not statistically influenced by adrenalectomy as measured by percent mating, ovulation, fertilization, and conception rate. When the three replications of the experiment were pooled, the number of viable embryoes was significantly reduced in the intact ewes compared to the adrenalectomized ewes (P<.07). The stressed intact ewes were found to have statistically heavier (P<.01) adrenal weights than those removed from the surgically operated ewes before heat treatment.