Several decades have already passed since the period of the basic geological-stratigraphic research on the Lower Cretaceous formations of the Western Carpathians by Dimitrij Andrusov. The first part of this work looks at the existing state of internationally recognized ammonite stratigraphy on the level of ammonite zones and horizons (subzones) and the placing of boundaries between stratigraphic stages and substages. The second part attempts to summarize recent findings from the area of ammonite stratigraphy of the ammonite-bearing Lower Cretaceous formations in the western part of the Outer and Central Carpathians, occurring on the Czech and Slovak territories.The summary is based above all on the author´s own collections in the field, his systematic study and revision of the older material and also on the results of cooperation with other specialists.