The mountain belt stretches from the Low Beskids range of the Eastern Carpathians along the border of Poland with Slovakia toward the Moravian region of the Czech Republic and the Austrian Weinviertel.

To the northwest and north they are separated from the Bohemian Massif by the Outer Subcarpathia and the Lesser Poland Upland; to the west the Moravian Gate leads over to the Sudetes.

The Western Carpathians are part of the northern branch of alpine orogeny, which was formed by the closure of the Tethys Ocean millions of years ago.

The northern boundary with the East European craton and Bohemian Massif is well marked by the thrust of nappes of the Carpathian Flysch Belt.

The oldest Paleozoic rocks experienced the first stage of deformation during the Hercynian orogeny, but younger Alpine overprint is common.