Three experimental groups have been constructed to evaluate the long-term outcome of fetal adrenal transplantation in rats. In Group 1 (n = 10), rats underwent bilateral adrenalectomy. In Group 2 (n = 10), rats underwent a sham procedure which included flank incision and arterial canulization. In Group 3 (n = 20), a left adrenalectomy was performed followed immediately by transplantation of a fetal adrenal graft into the greater omentum and marked with a prolene suture (Stage 1). One year later, the right adrenal gland of the recipient was removed followed by a determination of the fetal adrenal graft function (Stage 2). Craft function was evaluated by measuring ACTH and corticosterone levels; and a histologic examination of the transplanted fetal adrenal gland was obtained at autopsy.