The search for new highly effective analgesics is a topical issue of modern pharmacology since drugs currently used in clinical practice do not meet the requirements of efficiency and safety. Aim. To study of the effect of new derivatives of benzilic acid on the pain threshold using the “hot plate” test. Materials and methods. The objects of the study were new derivatives of benzilic acid. Determination of the pain threshold was carried out by the “hot plate” test. The substances studied were introduced orally as aqueous solutions in the dose of 12 mg/kg. The latent periods of the first licking of the paw sole and the first jump were recorded during the study. Results. Six- and seven-membered thienolactames did not show the analgesic activity, and acid benzilic amides yielded far exceeded their activity. Hence, formation of cyclic products led to a decrease of the activity. Introduction of the chlorine atom into molecules also led to the decrease of activity. At the same time, the structural modification of the amide group in thienopyrroles was effective. In the experiment the most active substance was KMS-49 containing the dimethylacetyl group. Another active compound was a derivative of KMS-284 belonging to other chemical group of compounds under study – benzilic acid amides. Conclusions. The most active compounds under research appeared to be KMS-49 and KMS-284 after their introduction the latent period of the first licking of the paw sole increased by 2.2 and 1.6 times, respectively; and the latent period of the first jump – by 2.8 and 2.5 times, respectively, compared to the control group at the significance level p ≤ 0.05.