The molecular assisted selection in animals is based on polymorphism study of desired gene alleles related to economic important traits, particularly productivity parameters. Allelic variants can be a result of different modification of DNA nucleotide composition, i.e. spot mutations leading to a single nucleotide polymorphism (SNP), insertions and deletions (indel), etc. Anyway, targeted selection necessitates detecting gene polymorphism and estimating its relationship with productivity. The genes encoding proteins which are involved in the growth and development regulation, such as hormones, are considered the most perspective and attractive candidates. So far as the physiological effect of any hormone is known to be directly related to its receptor, it is advisable to study gene polymorphism of both hormones and their receptors. In the Ukraine the relationship between polymorphism of the genes mentioned hereinabove and hen performance was not still studied. Therefore these stipulate the relevance and novelty of our investigation presented in the paper. The genetic structure of Poltava Clay chicken egg-and-meat breed (line 14, n = 98, laboratory population of State Poultry Research Station of the National Academy of Agrarian Sciences of Ukraine) was studied on growth hormone (GH), growth hormone receptor (GHR), prolactin (PRL) and prolactin receptor genes (PRLR).