Chemicals of the macrolide group – Pharmazin® and Tilotsiklinvet® – are widely used in veterinary practice in poultry farming for treatment or prevention in Ukraine. We have conducted a study on the pharmazin and tilotsiklinvet influence on the weight of broiler chickens before a slaughter; the weight of semi-dressed and dressed carcasses and internal organs of broiler chickens; the slaughter yield of broiler chicken carcasses and the ratio of their internal organs to a slaughter yield. Four groups of broiler chickens of the Cobb 500-day-old cross-breed were formed: two controls and two experimental (12 broiler chickens each). Chickens of the first experimental group were fed with pharmazin containing the active substance (AS) tylozine tartrate 500 mg per 1 g, and the second – with a tilotsiklinvet containing the (AS) tylozine tartrate and doxycycline glycate of 100 mg per 1 g of powder. Pharmazin and tilotsiklinvet were fed orally with a water at a dose of 1 g per 1 dm 3 of water according to the instructions for their use. These antibiotics were fed to broiler chickens with preventive purpose for the first 3 days of life, 28−29 and 38−42 days of the experiment. At the end of the antibiotics feeding, 6 broiler chickens from each group were slaughtered at the beginning of the elimination period (after 3 hours) and after the end of the withdrawal period (after 5−8 days), respectively, after the last pharmazin and tilotsiklinvet usage. It has been established that the use of pharmazin and tilotsiklinvet positively affects the productivity of chicken broilers. As a result, one can observe a significant increase in weight of broiler chickens before a slaughter (р≤0,001, р≤0,01) . S laughter yield increased by 8,2% when feeding pharmazin, and tilotsiklinvet – by 4,3%. Also, the weight of all the edible internal organs increased when using pharmazin and tilotsiklinvet (p≤0 , 05) and the weight of the liver and muscular part of the stomach when using tilotsiklinvet (p≤0 , 05).