Previous investigators have reported that premalignant changes in the form of abnormal germ cells can be detected in the cryptorchid and infertile adult testis. These cells are characterized by a thin rim of pale-staining cytoplasm, a large hyperchromatic nucleus and prominent nucleoli. We studied 113 biopsies from 102 patients to determine if these abnormal germ cells occur in the nonadult cryptorchid testis. The patients ranged in age from 3 months to 16 years. Evaluation of testicular tissue by light microscopy disclosed histological alterations in the undescended testis, which were those commonly ascribed to the undescended testis. However, none of the changes could be interpreted as premalignant. The abnormal germ cells described by other investigators were not found in any of these specimens.