Geological and petrophysical research focused on reservoir properties of Upper Jurassic carbonate deposits was carried out in the central part of the Carpathian foreland, also taking into consideration facies development and diagenetic processes. Petrophysical analyses of porosity, permeability (intergranular and fracture), and capillary pressure measurement were conducted on samples from 28 boreholes. Types and ranges of permeability and porosity were correlated with diagenetic processes (such as karst phenomena) on the basis of extracted lithofacies and regional tectonics. The best petrophysical properties are connected with organogenic buildups of the Upper Jurassic rocks. High values of intergranular permeability only occur on this type of rocks. Dual porosity-fracture permeability and fractures dominate other rocks. The karst phenomena improved storage and filtration properties of rocks.