This article provides information on new records of an alien powdery mildew fungus Erysiphe corylacearum (Erysiphales, Ascomycota), previously recorded in Ukraine only in Crimea and at two localities in Kyiv. In the end of September 2019, this species was additionally found in six sites of Hutsulshchyna National Nature Park (Ivano-Frankivsk Region, the Ukrainian Carpathians). This fungus has a primary East Asian-North American geographical range, but in recent years has started to occur in Turkey (2013), Azerbaijan (2016), Ukraine (2016), Iran (2017), southwestern Russia (2017), Georgia (2018), and Switzerland (2019). Therefore, it is concluded that this species migrated to Ukraine from the eastward. In the most of new localities, E. corylacearum significantly damaged common hazel (Corylus avellana) and abundantly produced fruiting bodies with asci and spores. Considering that this species is already recorded in the Ukrainian Carpathians and Switzerland and due to the ability of powdery mildew fungi to spread rapidly over new territories, it is expected that E. corylacearum will soon appear in various countries of Western Europe.