Construction began in March 2005, and the line was inaugurated by King Carl XVI Gustaf of Sweden on 4 December 2010.

The tracks switch sides in Arlöv around 5 km (3.1 mi) north-east of Malmö Central Station,[2] at a flyover constructed separately.

The task of investigating technology and cost of several options was assigned to Svedab AB (Svensk-Danska Broförbindelsen).

The opening of the new Triangeln underground station creates what will be one of the country's largest railway stations, with significantly reduced travel times from the region's cities to southern parts of central Malmö, including the large Malmö University hospital.

By the end of 2006, another construction site had been opened in Lockarp, where connecting tracks to Ystad and Trelleborg were being built.

The underground station at Malmö C was built in a 0.8 km (0.50 mi) long open trench which was then covered.

In order to build Triangeln station, two 25 m (82 ft) deep vertical shafts were dug at the northern and southern part of the site, and the station was then milled out of the rock by a roadheader — a machine equipped with a rotating cutter head on a telescopic arm.

In April 2008 the Swedish Transport Administration revised its forecasts, stating that "...the economic viability of many railway projects in the real world will exceed the previously estimated [sic].

[6] Trains in the City Tunnel will be controlled by the new ERTMS signalling system,[7] a new European standard simplifying operations across national borders.

Due to delays in equipment installation for integration between ERTMS and the older Swedish and (especially) Danish systems, there is a temporary arrangement using ATC.