The black locust (Robinia pseudoacacia L.) is among the first tree species that has been at the beginning of the 17 century introduced from North America to Europe. Shortly after its introduction it became widely distributed for its valuable properties across the whole Europe including the area of today’s Slovak Republic. Soon after its wide distribution and utilization the black locust appeared at sites away from its planed stands. At such sites the black locust became an unwanted and invasive species with significant negative impact on animal and plant communities. The aim of this study was to study the selected sites with the black locust presence at the sites in central and southern Slovakia (Štiavnické vrchy mountians and Krupinská planina plain) and identify its phytocenoses. The black locust forms four types of associations here: Chelidonio-Robinietum, Galio aparinae-Robinietum, Impatienti parviflorae-Robinietum and Bromo sterilis-Robinietum. Besides these findings two communities were identified: Alopecuro pratensis-Robinietum and Pruno spinosae-Robinietum. Our findings show that the black locust forms diverse plant communities at the studied region. The black locust fytocenoses are characterized by plants of semi shaded and semi lightened sites, which are distributed on dawns up to lower mountain range. These communities grow on wet moist neutral soils rich on nutrients.