Three types of microborings are described on corallites of auloporid corals from the Acanthopyge Limestone, Choteč Formation, Middle Devonian (Eifelian) of Central Bohemia. Straight unbranched galleries and swellings of Irhopalia isp. are interpreted as being produced by a phototroph, likely a chlorophyte. Two other rare ichnospecies likely represent sponge borings ( Entobia ? isp., Dendrina ? isp.). The microborings are preserved by the hydrated iron oxide mineral casts after pyrite fillings. The perfect three-dimensional preservation of the microborings represents an alternative for the resin casting method, which cannot be used in solid limestone, where the microborings are filled by precipitated calcium carbonate.