Ovarian function was assessed in 24 women after renal transplantation who were treated either with cyclosporin A (10 patients) or with a combination of azathioprine and prednisone (14 patients) as immunosuppressive therapy. The different regimens were not associated with any differences in clinical or endocrine indices of ovarian function (LH, FSH, prolactin, testosterone, oestradiol, dehydroepiandrosterone sulphate). Excessive hair growth was common in both treatment groups. Levels of testosterone and dehydroepiandrosterone were higher in cyclosporin-treated women but this was due to prednisone-induced suppression of adrenal androgen output in the azathioprine- and prednisone-treated women. Excessive hair growth was present in postmenopausal women on both treatments suggesting that hypertrichosis is a consequence of renal transplantation and is not a specific side-effect of cyclosporin A therapy.