It was built by the Rhine-Nahe Railway Company and connects Bingen am Rhein on the Left Rhine line with Saarbrücken.

The section south of Bad Kreuznach is part of the regionally important transport corridor between the two major cities of Mainz and Saarbrücken.

As early as 1839, there were plans to build a railway connection between the Saar and the Middle Rhine, which could not be realised due to high construction costs.

The Palatine administration originally considered that St. Ingbert, which was in Bavaria, would be at the western end of the line, but this changed under pressure from Prussia.

[5] In 1856 construction of the line was undertaken by the private Rhine-Nahe Railway Company (Rhein-Nahe Eisenbahn-Gesellschaft, RNE) set up for this purpose.

The Prussian government took control of the project on 18 June 1856 and issued the concession for the railway’s construction and operation to the company on 4 September 1856.

[6] In two places, however, the territory of two other countries had to be crossed: the Herrschaft of Meisenheim, which still belonged to the landgraviate of Hesse-Homburg, and the Principality of Birkenfeld, which was part of the Grand Duchy of Oldenburg.

While Oldenburg would have liked to see the line pass through the city of Birkenfeld, Prussia insisted on a route through the Nahe valley.

For tactical reasons, Prussia remained open-minded about these efforts, which led to Oldenburg giving way and accepting the route along the Nahe within its territory.

[8] This was followed by the sections to Oberstein on 15 December 1859[9] and to Neunkirchen (Saar) via Birkenfeld (now Neubrücke) and St. Wendel on 26 May 1860, with a total length of 52 or 53 km.

At first, there was a sharp competition with the Palatine Ludwig Railway, since both lines primarily served the transport of Saar coal.

Since the passenger traffic met the expectations of the builders only to the spas of Kreuznach and Münster, neither dividends nor interest on debt could be paid.

Because of the great military importance of the line, the RNE was acquired by the Prussian government with effect of 1 April 1881 and the company was dissolved.

Regentalbahn’s subsidiary vlexx GmbH now operates passenger services on the Nahe Valley Railway from Saarbrücken towards Mainz and Frankfurt.

A line ran from Laubenheim over the Hindenburg Bridge for thirty years (1915–1945), carrying traffic across the Rhine to Rüdesheim and Geisenheim.

[13] The Nahe Valley Railway is one of the main axes of rail passenger traffic in Rhineland-Palatinate and Saarland.

With the introduction of the concept of the Rheinland-Pfalz-Takt 2015 (Rhineland Palatinate clock-face timetable) in the middle of 2008, services on the Nahe Valley Railway were improved.

[14] The following stations on the Nahe Valley Railway are planned or under consideration (this does not include Baumholder, Heimbach Ort and Ruschberg, which are on the branch line): The Nahe-Express from Frankfurt am Main to Saarbrücken would possibly be split or coupled every hour in Bad Münster am Stein.

The Nahe Valley Railway runs largely parallel to federal highway 41 and their paths cross several times.

South of Namborn the railway line crosses the road again and the two run parallel with the course of the Blies between St. Wendel and Ottweiler.

The section between Türkismühle (line-kilometre 89.0) and Saarbrücken Hauptbahnhof has been electrified since 1969 and the Saarbrücken–Neunkirchen line via Fischbach-Camphausen (Fischbach Valley Railway) has been operated electrically since 1965.

In the summer of 2012, the section of the line between Neunkirchen and Saarbrücken was closed to allow renewal of the track and repair work on the Bildstock Tunnel.

Regional-Express and freight trains were diverted via the Fischbach Valley Railway and the remaining passenger services were replaced by buses for the duration of the work.

After the line was electrified, services were mainly operated with Silberling carriages hauled by class 140 and 141 electric locomotives.

With the establishment of the Gau Algesheim–Bad Kreuznach railway, it lost passenger services, but remained as a freight yard.

With the opening of the strategic railway to Bad Münster, the section between Odernheim and Staudernheim became essentially a connecting curve.

With the electrification of the Nahe line to Neubrücke, it has serves as the terminus of RB 73 services from Saarbrücken since the timetable change on 14 December 2014.

It was not until 77 years later that the Oster Valley Railway (Ostertalbahn) opened to Niederkirchen, making it a junction station.

Because freight train branch off at the station to the Saarbrücken marshalling yard, the line from Dudweiler-Jägersfreude section has three tracks.

Until the end of the millennium, Jägerfreude was also a railway junction, which was controlled from the signal box in Saarbrücken Hbf.