Abstract The southern Alps are divided into five distinct zones formed during the geosynclinal stage: the Lombardian depression, the Tridentine ridge, the Belluno depression, the Friuli ridge, and the Julian depression. Transition zones can be defined between the units. Late geosynclinal deposition (Miocene) is best represented in the Friuli ridge zone. Post-geosynclinal deposition corresponding to Pliocene-Quaternary deposits is equivalent to that of the Po river plain. Geosynclinal and late geosynclinal evolution was marked by folding perpendicular to earlier tectonic trends. Post-geosynclinal folding (Pontian to Pliocene) was oblique or perpendicular to the preceding structural patterns. A correlation is made between the southern Alps and the Italian Dinaric Alps north of Lombardy and Venice; the geosynclinal deposits are correlated with the Dinaric molasse sequence; and post-geosynclinal events are related to the Po plains. It is believed that the eastern Alps are the 'true' Alps whereas the western Alps are a part of the Italian Dinaric Alps.