In the androgen insensitivity syndrome (AIS) the androgen effect is decreased in the fetus and the youth despite the adequate testosterone production. Usually the mutation of the androgen receptor is responsible for the disease. In the presented case the external genitalia were similar to female genitalia but masses were palpable in the labioscrotal fold. The karyotype was 46,XY. There was no increase in the testosterone level during the first three months of life. The stimulation test by stanazolol and the androgen receptor gene analysis verified the androgen insensitivity. The mutation was absent in the mother's leukocytes. This fact makes the genetic advising difficult in this family.