The article highlights the project results on the assessment of the impact of middle voltage overhead power lines (PL) on avifauna of Mangistau region of the Republic of Kazakhstan. On repeated examination of 440 km of PL there was determined a fact of death of 123 birds belonging to 29 species. In particular, 23 birds died from injuries because of collision with wires, and 100 birds were electrocuted. Among the latter, about 60 % are eagles (Steppe Eagle Aquila nipalensis, Golden Eagle Aquila chrysaetos, Imperial Eagle Aquila heliaca). There is the dependence of a number of electrocuted birds on the engineering design of PL. There was an extrapolation of the bird electrocution survey results on the whole territory of Mangistau region.