Maldescent is known to increase the risk of cancer of the testis. However, the effect of orchiopexy on reducing tumour risk and altering tumour type or stage at diagnosis is not established. The authors review the records of patients with testicular tumours seen for seminoma (1958 to 1975) and nonseminoma (1958 to 1970). Of 646 patients, 53 (8.2%) had a history of testicular maldescent; in 42 (79%) the maldescent was unilateral and in 6 of these, the tumour developed in the normally descended testis. Twenty patients had successful orchiopexy at a median age of 14 years (range from 6 to 35 years). Tumours found in the 53 patients were seminoma (38 patients), teratoma (7 patients), embryonal carcinoma (6 patients), teratocarcinoma (1 patient) and choriocarcinoma (1 patient). Average age at the time of diagnosis of seminoma was 38 years and of nonseminoma 31 years. Average age was lower at the time of diagnosis of the tumour for those who had successful orchiopexy than for those who did not. Earlier stage nonseminomas were found in patients who had an orchiopexy. Twenty-five (66%) of the 38 seminomas occurred in testes located outside the scrotum, whereas only 6 (40%) of 15 nonseminomas occurred in a nonscotal position, suggesting that persistent maldescent favours seminoma over nonseminoma. In this retrospective review, no statement can be made about the effect of orchiopexy on tumour risk. However, this procedure appears to lead to an earlier diagnosis and may influence the type of tumour that subsequently develops.