The aim of the research was to determine in the experiment the content of catecholamines in serum of rats exposed to sodium fluoride. The studies were conducted on adult Wistar rats, subjected to oral exposure by means of a probe with aqueous solutions of sodium fluoride (SF) once daily, for 60 days at doses of 1/10, 1/100 and 1/1000 DL50, which correspondingly amounts to 20 mg/kg, 2 mg/kg and 0.2 mg/kg of body weight. Toxification of rats at a dose of 1/100 DL50 for 60 days and at a dose of 1/10 DL50 for 50 days was accompanied by an increase in blood levels of norepinephrine and epinephrine, indicating the hyperactivation of the mediator and hormonal parts of the sympathoadrenal system, and tension of the protective and adaptive reactions of the organism. Prolonged hypercatecholemia may become a pathogenic factor due to intensification of the quinidine route of oxidation of norepinephrine and epinephrine with the formation of reactive radicals and active forms of oxygen. Reduced serum content of catecholamines on the 60th day of oral administration at a dose of 1/10 DL50 reflects, on the one hand, a decrease in their tissue deposit, and, on the other, a decrease in the activity and reserve capacities of the sympathoadrenal system.