The infertility is a important health problem, affecting about 10-15% of couples. The important role of genetic factors in pathogenesis of infertility is now increasingly recognized and our knowledge in this field are improved each day. For these reasons we review the most important genetic causes of infertility. In this paper we analyse the genetic implications in gonadal and postgonadal infertility. Gonadal infertility affects both sexes and are characterised by hypergonadotrophic hypogonadism. Gonadal infertility is produced by chromosomal or monogenic mutations. Chromosomal causes are represented by gonosomal aneuploidy and structural chromosomal abnormalities. The monogenic disorders are consequences of a recessive mutations of hormone, hormonal receptor or enzymes genes. Postgonadal infertility is present in men and is the result of some obstructive disorders.