In 1912, the Dümpelfeld–Hillesheim (Eifel)–Lissendorf line was opened; this followed the upstream half of the Ahr and then branched off into the Ahlbach valley at Ahrdorf.

At the same time, the original line was partially relocated and the Ahr Valley Railway was double-tracked from Remagen to Liers junction.

Construction was commenced on other new lines, such as the "strategic railway" that was intended to connect the Ahr valley from Dernau with Neuss via Rheinbach and Liblar bypassing Cologne, but they were not completed due to the First World War and the subsequent disarmament imposed under the peace treaty.

During the Second World War, the already completed tunnels in the Ahr valley were used for the armaments industry, using forced labour, and were redeveloped between 1960 and 1972 as the German federal government bunker.

The construction of the Siegfried Line gave the Ahr Valley railways great strategic importance.

In December 2013 LINT 81 (DB Class 622) took over the service scheduled for 20 years as part of the Vareo-branded regional rail network.

[3] The Ahr Valley Railway is served by the following services: Currently, these only run as far as Walporzheim, with replacement buses on the rest of the route.

Services on the line are operated by DB Regio NRW using class 622 (Bombardier Talent) diesel multiple units at speeds of to 120 km/h.