Grape pomace is the main production residue from processing grapes into wine and contains significant levels of polyphenolic compounds, which can be used in various pharmaceutical, cosmetic and food products due to their biological activity. Polyphenolic compounds have a positive effect on human health due to their antioxidant, anti-inflammatory and antimicrobial activity; however, the method of isolation from the plant material affects the possibility of their further use. Microwave extraction is often used as an alternative to conventional solvent extraction because of its economic and energy advantages (e.g., shorter process time, lower solvent consumption). In this work, the influence of the volume fraction of ethanol (0-100 % v/v) in an aqueous ethanol solution the solid-liquid ratio (5-10 mL/g), and the extraction time (15-25 min) on the yield of polyphenolic compounds was investigated. The optimal extraction conditions were determined using the response surface method. A quadratic polynomial was successfully used to describe the microwave extraction of polyphenolic compounds, which showed good agreement with the experimental data, as evidenced by a high correlation coefficient (R > 0.98). The optimal conditions for microwave extraction were determined by numerical optimization: the volume fraction of ethanol in the aqueous ethanol solution was 57 % v/v, the liquid-to-solid ratio was 10 mL/g, and the extraction time was 25 min. It was calculated that a maximum yield of polyphenolic compounds of 65.93 \( mg_{GAE}/g_{db} \) could be obtained under the above conditions.