Diabetes is a growing public health problem. Many studies have confirmed the benefits of medicinal plants with a hypoglycemic effect in the treatment of diabetes. The effect of these herbs can delay the development of diabetes complications and correct metabolic abnormalities. The aim of this study was to test the ability of essential oils and hydrolats of selected plant species to inhibit the α-glucosidase enzyme, using the Sigma-Aldrich method. The content of total phenolics was determined by the Folin-Ciocalteu method for the hydrolate samples. The results showed that the most effective inhibitor among the tested hydrolats was that of the Juniperus communis spp. nana plant (IC 50 =47.89 mg/L). Other samples at all tested concentrations weakly inhibit the enzyme. Among essential oils, the best inhibitor of α-glucosidase enzyme is the oil of the plant Hymenocarpos circinnatus, which at a concentration of 1 g/L inhibits the enzyme by 52.16 ± 3.82 %. Centaurea scabiosa with 38.72±11.05 % and Mantisalca salmantica with 32.2±12.72 % had a slightly lower inhibitory effect at the same concentration, while the essential oil of Campanula rapunculus showed no inhibitory effect on this enzyme. The highest total phenolics content was found in most effective inhibitor; hydrolate of the plant Juniperus communis spp. nana (196 mg GAE/g hydrolate), while for the other tested hydrolats there is no significant correlation between total phenolics content and enzyme inhibition.