Abstract The American bolete Aureoboletus projectellus was first reported in Europe in the first decade of this century. At the beginning, it was only observed on the Baltic Sea shore. Since 2014, the range of this fungus has been significantly expanding, at present it reaches more than 150 km inland and encompasses five countries. Recently, mass occurrences of its fruit bodies were observed in Latvia, Lithuania, and Poland. A. projectellus forms mycorrhizas with native European trees in the range of their natural distribution (Pinus sylvestris) as well as in the areas where they were introduced (Pinus mugo).