Many pharmaceutical products on the market contain propolis, usually added in the form of ethanolic extract. Because of possibility that during preparation of propolis ethanol of inadequate purity was used or was inadvertently replaced with denatured ethanol, there is a possibilily of contamination affecting the quality and safety of the finished products. The expected and most commonly found contamination in ethanol is methanol. Because of potential toxic effects of ethanol and methanol, goal of this thesis was to determine content of methanol and ethanol in pharmaceutical products with propolis using gas chromatography with headspace sampling. This technique was chosen because it allows analysis of volatile compounds in complex samples with very little pretreatment of samples. A previously developed and validated HSS GC-FID method for determination of ethanol and methanol content in liquid samples was used for analysis of 24 samples with propolis. Data on content of ethanol and methanol was obtained by calculation using calibration equations. Based on the results, it was found that all analyzed samples contained ethanol in a range from 0.01 to 75.96% v/v. In some samples which contained a large amount of ethanol, methanol was found, as expected, ranging from 0.003 to 0.026% v/v. In most of analyzed samples ethanol was not declared, or it´s amount was incorrectly listed, even in products intended for children. Methanol, found in several samples, did not exceed the permitted levels. Although determined quantites of ethanol were not dangerous for adults, much smaller amounts can cause acute poisoning in children. According to guidelines some of the tested products should not be used in children and need to be packaged with a safety cap. As these poducts are not subject to strict legal regulations as medicines, and because general attitute and belief is that those supplements are natural and hence safe products, consumers pay less attention to correct dosing and storage of such products. Results of this thesis indicate that regular inspection of these products is needed.