In 1866, the BME opened the line from Unna to Hamm to connect with the Cologne-Minden trunk line.[6] Later the line was extended from Unna to Hagen, making Unna station into a railway junction of regional importance.[7]
Between 1899 and 1901 the Prussian state railways opened the Fröndenberg–Kamen railway to connect the three east-west lines in the area.[8][9] The southern part connected with the line to Menden, which was opened in 1872; this line was extended in 1912 to Neuenrade as the Hönne Valley Railway. The northern part was opened later for freight in 1900 and a year later for passenger traffic. This route is now worked only as far as Unna-Königsborn, as line S 4 of the Rhine-Ruhr S-Bahn.
Unna station is served by the Rhein-Münsterland-Express (RE 7, at 60-minute intervals), the Maas-Wupper-Express (RE 13, at 60-minute intervals), the Hönnetalbahn (RB 54, at 60-minute intervals), the Hellweg-Bahn (RB 59, at 30-minute intervals) and Rhine-Ruhr S-Bahn line S 4 (at 30-minute intervals). The station also serves as the central bus junction for the city.[10]