Extraction of polyphenols from sea buckthorn leaves using microwave-assisted extraction MAE) is described. The influence of different parameters on the extraction process reactor type, stirring rate, extraction time, temperature, ethanol/water ratio) was studied. The polyphenolic extracts were analyzed in order to determine the total phenolic content TPC) either by the Folin-Ciocalteu method or by differential pulse voltammetry DPV), and the concentration of the main polyphenolic compounds by high-performance liquid chromatography HPLC). The specific microwave energy was also determined. MAE resulted in a shorter extraction time 7.5 versus 30 min for the conventional method). The best results for MAE were obtained at a temperature of 90 degrees C, using a solvent/plant ratio of 20/1 and 50% ethanol in the extraction solvent. The highest values of antioxidant capacity were obtained for polyphenolic extracts resulted from microwave extraction.