Studies were conducted in private poultry farms in five economic regions of the Republic of Azerbaijan: Apsheronsky, Sheki-Zakatalsky, Lenkoran-Astarasky, Guba-Khachmazsky and Aransky. It was found that helminthocomplex of domestic chickens is represented by parasites belonging to class Nematoda, including 4 species - Ascaridia galli, Heterakis gallinarum, Syngamus trachea, Capillaria obsignata and Cestoda, represented by one species, Raillietina tetragona. Their ubiquitous distribution has been established; however, with a homogeneous taxonomic composition in economic areas, the infestation of chickens with pathogens of individual helminthic diseases varies. Ascaridia galli and Heterakis gallinarum are the dominant species. Their invasion of hens is maximum (36.8 and 35.5% prevalence) and does not have significant territorial differences. Bird infestation with nematodes C.obsignata and tapeworms Raillietina tetragona is characterized by lower prevalence rates and their pronounced variability within areas. The infestation of chickens with capillariasis and ryetinosis varies from 7.1% in Aransky district to 28.8% in Lenkoran-Astarsky district, from 5.4% to 24.8% in Apsheronsky and Guba-Khachmazsky districts. On average, it is 17.8 and 18.5% in the republic, respectively. Age peculiarities of chickens' helminth infestation are characterized by the same taxonomic spectrum of parasites and maximum infection with the causative agents of ascariasis, heterokidosis, syngamosis, capillariasis and ryetinosis in chickens aged 2.5-5 months with prevalence of 38.9; 40.8; 21.9; 19.7 and 20.9%, respectively. The incidence of these nosoforms in adult birds is much lower and amounts to 32.0; 30,8; 15,3; 16.2 and 16.0%.