BACKGROUND Cryptorchidism is a common malformation in neonates; surgery or medical treatments are applied during childhood. Untreated cryptorchid testes are in the risk of intratubular germ cell neoplasia (IGCN) and consequently invasive testicular tumors which could be shown by immunohistochemistry staining for placental like acid phosphatase (PLAP) marker. OBJECTIVE We designed this study to know the prevalence of IGCN in untreated cryptorchid testes of infertile men, in our infertility center as a refferal center. METHODS In this cross-sectional study we assessed H&E slides of testicular samples of 13 adult infertile patients with impalpable intra-abdominal testes seeking infertility treatment; then we stained them by PLAP marker. RESULTS Three (23.08%) samples were positive for PLAP marker means presence of IGCN in testis. One of them showed seminoma besides IGCN. CONCLUSIONS According to the results of this study and the fact that there are adult untreated cryptorchid patients in our country yet, it is suggested to pay more attention in clinical examination, assessment and follow up of such patients for malignancy screening.