The line was originally built for freight transport, but now carries mostly InterCity and EuroCity long-distance passenger services from cities in the southern part of the country such as Katowice, Kraków, Wrocław, Opole and Częstochowa to Warsaw.

The CMK was constructed between 1971 and 1977, as a freight line designed to haul coal from Upper Silesia and the Dąbrowa Basin to the ports of the Tricity.

However, the economic crisis in mid-1970s Poland changed these plans, and the CMK ends at Grodzisk Mazowiecki, where it connected to the already-existing PKP line 1 formed from the former Warsaw–Vienna railway.

[1] The idea of the construction of a direct rail connection between Upper Silesia and Warsaw was first proposed by professor Aleksander Wasiutyński[2] in the 1920s.

He rightly noted that the Warsaw–Vienna railway, which goes to Warsaw through Zawiercie, Myszków, Częstochowa, Radomsko, Piotrków Trybunalski, Koluszki, and Skierniewice, would not be able to carry all the passenger and freight traffic between the two industrial centers of the newly reestablished country.

The idea was abandoned when the government constructed the Polish Coal Trunk-Line instead connecting Upper Silesia directly with the port of Gdynia, bypassing Warsaw.

The decision to begin construction of the 143 km (89 mi) Zawiercie - Radzice connection was taken in June 1971, and the first works began in August of that year.

After completion of the track from Zawiercie to Grodzisk, construction of a Warsaw - Gdańsk Port Północny (via Wyszogród, Płock, Sierpc, Brodnica and Malbork) connection was planned, but abandoned in the late 1970s and early 1980, due to the ongoing financial crisis in Poland.

[13] In early 2014 installation of 13 high-speed railroad switches (points in British terminology) of the most modern type was carried out at Szeligi [pl] on the CMK some 22 km south of Grodzisk Mazowiecki.

The installation at Szeligi was carried out by the Polish subsidiary VAE Polska of the Austrian supplier Voestalpine Weichensysteme GmbH.

The Pendolinos reach 200 km/h (124 mph) on a total of 133 kilometers of the CMK, divided into two disjoint sections; the first regularly scheduled operation at 200 km/h in Poland.