Edible seed squash (Cucurbita pepo L, ESS), which is grown for its seeds to consume as a snack, has a very important place in vegetable production in Türkiye. Viruses are one of the most problems in the cultivation of ESS in the country. One of these diseases is Watermelon mosaic virus (WMV, Potyvirus, Potyviridae). Also, it’s very common and devastating on other cucurbits worldwide. Propolis, which is composed mainly by the plant resins and exudates that honey bees gather, showed antiviral activity against plant and human viruses. In this study, the potential of propolis to control WMV was investigated by taking advantage of these antimicrobial properties of propolis. For this purpose, propolis extracted with 95% ethanol and diluted in distilled water to obtain different concentrations as 2, 4, 6, 8 and 10% were used. Effects of propolis against WMV were determined by in vitro and in vivo studies. Except of 2, and 4%, all concentrations caused to symptoms reductions of the infection, in all studies. In the result of in vitro studies, the ratios of healthy plants were calculated as 10, 20, 40% and 20, 30, 50% after one and two hours, respectively. In vivo, by spraying concentrations of 6, 8 and 10% before inoculation obtained healthy plants as 20, 40 and 60% after one-hour period, and as 20, 30 and 50% after two-hour period, while the extracts sprayed after inoculation, ratios of healthy plants as 10, 20 and 30% after one-hour period, and as 10, 20 and 20% after two-hour period. According to the results of the study, it was determined that applications of different propolis concentrations had the potential to reduce WMV infection, and these results should be supported by field trials.