Flightless Transylvanian Dark Bush-cricket Pholidoptera transsylvanica is subendemic to the Carpathians and the Pannonian basin and one of ten species of European Community interest. In the last few years we have increased survey efforts aimed to obtain distributional data for this species along the northern range margin in Western Carpathian mountains covering most of Slovakia and reaching also south of Poland. Thus in Slovakia, where only 5 sites were known in 1996, 56 sites are known in 2017. The species was discovered for the first time in Poland in July 2017, in two sites in the south-eastern part of the country. Both sites are located in submountain mesophilous meadows of the alliance Arrhenatherion elatioris Luquet 1926, in its various successional stages along mainly mixed forests dominated with European beech and in alluvial vegetation. The presence of the species in these new sites is at the northern edge of its distribution area, and we suppose that only lack of data and no surveys in the past caused this knowledge gap. Data on its habitat and main threats and conservation measures of the species are discussed, and accompanying orthopteran species are characterised.