The aim of this article was to study the effect of quercetin combination with T-2 toxin to secretion of thyrotropin and thyroxine in vivo. The rabbits were divided into the control group (without quercetin and T-2 toxin), and four experimental groups with different doses of quercetin. The thyrotropin (TSH) secretion was not significantly affected by intramuscular application of quercetin and T2-toxin against control group. The secretion of TSH was non-significatly decreased by addition of T2-toxin (group 1), but it was increased after application of quercetin with T2-toxin (groups 2, 3, 4). Significant differences between control group and experimental groups were not observed in thyroxine (T4) secretion. The highest concentration of T4 was observed in group 3 and the lowest in group 2. Our results suggested protective effect of quercetin on TSH secretion.