To determine the impact of liver transplantation on andrological status, we compared the endocrine profiles and spermiograms of 2 cohorts of patients before (9) and after (11) transplantation. Before liver transplantation testosterone (1.1 +/- 0.7 ng/ml) and free testosterone (2.0 +/- 1.6 pg/ml) were pathologically decreased in all 9 cases, and luteinizing hormone was lower (1.8 +/- 1.4 mIU/ml) in 5. Only 3 of 9 patients were able to produce ejaculates before liver transplantation, all of which were azoospermic. After a mean interval of 28 +/- 9 months (range 4 to 34 months) following liver transplantation testosterone (5.3 +/- 1.1 ng/ml), free testosterone (15.3 +/- 5.0 pg/ml) and luteinizing hormone (6.2 +/- 3.7 mIU/ml.) were consistently within the normal range, with a highly statistically significant difference (p < 0.025) from pre-liver transplantation values. Semen analyses after liver transplantation revealed normal density, motility and normal forms in 5 patients, 2 suffered from oligoasthenoteratospermia and 4 were unable to produce an ejaculate for semen analyses. These data demonstrate that the hypothalamic-pituitary-testicular hormone axis and gonadal tissue are capable of resuming normal function after liver transplantation in men with chronic liver failure who suffered from massive andrological dysfunction before transplantation.