We report two cases with ichthyosis vulgaris, hypogenitalism and hypogonadism. So far, little endocrinological information has been available on this association and the exact type of ichthyosis was unknown. Our first patient suffered from very severe hypergonadotropic hypogonadism, whereas the second patient showed normal levels of luteinizing hormone, but slightly elevated follicle stimulating hormone values. In lipoprotein electrophoresis we found fast moving beta‐lipoproteins in the first patient and a normal electrophoretic mobility of pre‐beta and beta‐lipoproteins in the second patient. Correspondingly, steroid sulfatase (STS) testing revealed STS deficiency in the first patient and normal STS activity in the second patient, thus excluding X‐linked recessive ichthyosis. These two different types in the association of ichthyosis with hypogenitalism and hypogonadism could not be discriminated by clinical, morphological and cytogenetic