The planning of the line started in 1873, but not until November 19, 1927 was the line opened by King Haakon VII and Crown Prince Olav. The background for the line was the need of transport created by Noreverkene. Originally the line was thought of as a possible part of Bergensbanen, but instead Bergensbanen went through Hallingdal. The line utilized steam propulsion until 1970, after which diesel trains were used until the line was closed on December 31, 1988.
After the closing Numedalbanens Friends arranged some tourist traffic for a few years, but then given up. Large parts of the line are no longer suitable for operation due to lack of maintenance, but the line is still remains. There is some rental of draisine. The stretch from Flesberg to Rødberg is suggested preserved as a cultural heritage.