The article describes the experiment to determine allergic effect of a new probiotic drug vetom 21.77. The experimental studies consisted of two parts: an intradermal allergic test and a conjunctival allergic test. Experimental animals of the same sex were used in an amount of 40 rabbits at the age of 7–8 months. During the intradermal allergy test vetom 21.77 was injected intradermally (at a therapeutic dose and at a dose 10 times higher) with the animals of 2 pilot groups. The procedure of the conjunctival allergic test consisted in instilling of 0.1 ml of vetom 21.77 in the left eye of each animal from a pilot group in doses according to the procedure. The preparation was injected into the lower conjunctival sac of an eye. Physiological state of the experimental animals did not change during the study; their 100% safety was established. According to our research, vetom 21.77 pertains to hypoallergenic drugs.