To report confirmed cases of spontaneous testicular ascent in patients with a cryptorchid testis which had been previously placed in the scrotum. Between 1972 and 1992, 46 cryptorchid testes (36 patients), which were previously verified to be in the scrotum by staff paediatricians or paediatric surgeons, were treated surgically. The clinical, surgical and anatomicopathological records were reviewed to determine testicular position and associated conditions, and biopsies were taken from 35 testes. The mean time between the last "normal' exploration until the testes ascended was 4.5 years. Before ascent, the testes were confirmed to be in the scrotum by up to seven separate recorded examinations. During surgical treatment, an open processus vaginalis was found in 18 testes. The mean (SD) tubular fertility index was 40 (37)%. This study confirms that a previously descended testis can ascend spontaneously. The clinical and anatomicopathological characteristics of these testes were similar to those of the cryptorchid testis.