The paper discusses karstification along the thrust contact between dolomite and limestone at Idrijski Log and Koševnik (west-central Slovenia). Thrust contact induced the formation of a specific contact karst assemblage. Karst morphology is less strongly expressed within the dolomite, whereas the limestones are deeply karstified, with many dolines, shafts and sinkholes. Shafts in limestone and dolines in dolomite show genetic relationship with the thrust contact, whereas preserved fragments of phreatic features originated deep beneath the thrust plane.