Testis homotransplantation has been carried out in 11 patients since 1986. Of them, 8 suffered from congenital testicular dysplasia and the other 3 from orchiatrophy as a result of orchitis. Preoperatively, manifestations were a small penis, small testes, sexual dysfunction, indistinct secondary sex characteristics and low serum testosterone (1.7-7.35 mmol/L). Three cases had cadaver transplants and 8 had living relatives' transplants. The patients were followed up for 7 months to 4 years. The secondary sex characteristics and sexual function were improved remarkably after transplantation. Serum testosterone increased up to 12.8-18.2 mmol/L. All of 5 married patients resumed sexual intercourse satisfactorily. Three others got married after transplantation and have enjoyed normal sexual functions. Spermatozoa have been found in the semen in 3 of the cases.