A 2-week-old newborn presented with bilateral cryptorchidism and normal male external genitalia. At age 1 year and 4 months, he underwent laparoscopic surgery, which revealed a uterus and fallopian tubes. A unique homozygous T to G base substitution was found at position 2219, near the middle of the exon 5, changing codon CTG to CGG in anti-Mullerian hormone (AMH) gene.Both parents are heterozygous for the mutation. This evidence concerns the gene AMH and cryptorchidism.