Conodont elements from Palaeozoic strata (Ordovician, Devonian and Carboniferous) contain abundant evidence for presumed post-mortem colonisation by endolithic organisms. It is possible to distinguish several morphotypes of microcavities in conodont apatite, whichshow some morphological similarities to microborings in calcareous substrates. Some of them are believed to be produced by microendoliths,some others are yet unknown from calcareous substrates. The present report deals with the various kinds of microendolithic traces in conodontapatite. The significance of microborings in conodont elements is discussed.