A five-year-old boy was operated upon for left-sided cryptorchidism. Failure of uro-genital union was found with the left testis and caput epididymidis intra-abdominally situated, and vas deferens and the rest of the epididymis in the lower part of the inguinal canal. The risk of development of malignancy in an intra-abdominal testis has been calculated to be one in 20. If it is impossible to find a testis in the inguinal canal or just inside the internal ring in a patient with cryptorchidism, the peritoneal cavity therefore must be opened and the abdomen carefully explored. The finding of a blind-ended vas deferens with epididymal tissue in the inguinal canal does not exclude an intra-abdominal testis.