The following associations of xerothermic oak forests were recognized in the Slovakian side of the Biele Karpaty Mts., the Čachtické Hills, the Povážsky Inovec Mts., and the Strážovská hornatina Upland: (1) Pruno mahaleb-Quercelum pubescentis Jakucs et Fekete 1957 - the most xerophilous and thermophilous open forests of southern slopes on limestones and dolomites of Pannonian phytogeographical region. (2) Seslerio albicantis-Quercetum pubescentis ass. nova - xerophilous and thermophilous open forests of southern slopes on limestones and dolomites at higher altitudes under influence of Carpathian phytogeographical region. (3) Corno-Quercetum Máthé et Kovács 1962 - moderately xerophilous and thermophilous forests on limestone and dolomite slopes occurring on less xerothermic habitats and in marginal areas of the Pannonian phytogeographical region. (4) Festuco heterophyllae-Quercetum Neuhäusl et Neuhäuslová-Novotná 1964 - moderately xerophilous and thermophilous forests on sunny slopes on poor crystalline rocks, representing a transition to oak-hornbeam forests. (5) Potentillo albae-Quercetum Libbert 1933 - moderately thermophilous forests of flat terrain on loamy substrata with changeable soil humidity regime.