The frequency of homozygous congenital adrenal hyperplasia in Tyrol is found to be 1 : 8991, the gene-frequency for congenital adrenal hyperplasia 1 : 95 and the frequency of heterozygous congenital adrenal hyperplasia 1 : 48. Our data is compared on a numerical and statistical base with that in Zürich and Munich with regard to the frequency of congenital adrenal hyperplasia, to its distribution with and without salt loss and to its sex-distribution. According to our study one may assume a frequency of homozygous congenital adrenal hyperplasia in Tyrol, Zürich and Munich of 1 : 7000--10,000.