The line runs through the region of Holstein and connects the cities of Hamburg, Elmshorn, Neumünster and Kiel.

[2] The 105 km (65 mi) long standard gauge double track electrified railway line is now owned by DB Netz.

The Marsh Railway to the North Sea coast and the line to Henstedt-Ulzburg branch from Elmshorn.

Further north in Neumünster the line connects to Flensburg, to Heide and Büsum and to Bad Oldesloe.

The opening of the Hamburg-Altona link line in 1866 made it possible for the first time for trains from Kiel to Hamburg Hauptbahnhof.

DB Regio operated the service with class 648 multiple units again, which was intended to rationalise rolling stock circulation.

Between Hamburg, Neumünster and continuing to Flensburg, there are four daily Danish IC3 services each way on the Hamburg–Fredericia route (due to train path conflicts these trains not stop in Neumünster, but instead stop in Hamburg-Dammtor and Schleswig) and Intercity services operated with an electric locomotive of classes 101, 120 or 182 with seven to ten passenger cars.