One of the most actual problems of modern poultry farming is to increase the preservation of chickens and ensure high intensity of their growth at all stages of rearing. The development of alternative methods of prevention and treatment of infectious diseases of poultry involves the use of preparations of natural or organic origin, which have antagonistic properties against infectious agents and are able to balance the immune response. A prominent place in the system of disease prevention and increasing the resistance of animals and poultry is the development of modern probiotic and bactericidal preparations. In view of this, we studied the influence of the synbiotic preparations “Biomagn” in combination with the disinfectant “Diolide” on the state of the T- and B-cell links of the specific immunity of broiler chickens during the period of their rearing. The preparation “Biomagn” is based on representatives of the normal commensal microflora - non-pathogenic lactic acid bacteria with antibacterial and immunomodulatory properties and additional components: magnesium chloride, chitosan, xylanase, protease, cellulase, milk thistle meal, acidity regulator, betaine and emulsifier. The specified remedy is used to ensure optimal level of metabolism, increase immune function, growth, safety of animals and poultry. The results of the research showed that the use of the synbiotic preparation “Biomagn” in combination with the disinfectant “Diolide” had a positive influence on the activity of T- and B-cell links of specific defense of broiler chickens organism during the period of their rearing. This is evidenced by an increase in the amount of T-lymphocytes (total, active and theophylline-resistant) and B-lymphocytes in the blood and an increase in their functional activity due to the redistribution of the receptor apparatus of immunocompetent cells. In particular, a decrease in the number of functionally inactive T- and B-lymphocytes in the blood and an increase in the number of cells with low and medium degree of avidity. Therefore, the use of a set of studied immunotropic preparations is a promising direction in increasing the resistance and productivity of poultry. This allows in industrial conditions of maintenance, without loss of productivity, to respond to technological factors that can lead to immunodeficiency, disease and death of poultry.