Stable isotope compositions of the Early-Middle Eocene limestone were studied in the Prolom quarry (45.105°N; 34.736°E). Samples were collected across a 25 m-thick bed, at 1 m increment. Oxygen and carbon isotope values show little variation across the entire thickness of the bed. The dataset presents the isotope values characteristic of the unaltered limestone forming at shallow depth (nummulite bank) on the Early-Middle Eocene carbonate platform.