The line 10 is one of the longest tram lines in Europe. The 26 km long narrow-gauge line stretches from Rodersdorf (Solothurn canton) to Dornach through Basel city and the canton of Basel Landschaft. The travel time is 63 minutes. Today's line 10 was created by joining two narrow-gauge railways, the Birsigtalbahn (Rodersdorf - Heuwaage) and the Birseckbahn (Aeschenplatz - Dornach). The first section of the Birsigtalbahn (BTB) was opened in 1887. It was electrified in 1905, with 750 V DC. The line reached its full length in 1910, when the last section (Flüh-Rodersdorf) was inaugurated. The Birsigtalbahn - since 1974 part of Baselland Transport AG (BLT) - was adapted to operate with trams in 1984, and got the line number 17.

The other line, Birseckbahn (BEB) was opened in 1902, its outer terminal was Dornachbrugg (the section Dornach Bahnhof - Dornachbrugg was closed in 1969). This was the original line 10, operated by Basler Strassenbahnen. The line became a private railway in 1916, and operated as Birseckbahn until the fusion of the public transport companies in the surroundings of Basel in 1974, when - as tram line 10 - it was taken over by the newly founded Baselland Tranport AG (BLT).

The separated tram lines have been joined in 1986. The line 17 was linked to the tram network of Basel at Heuwaage with connection tracks. At Theater stop, a new connection to Bankverein was built (before, trams could only turn to Barüsserplatz). Since then, the new line 10 merges the branches of Rodersdorf and Dornach through the city center of Basel.

Between Flüh and Rodersdorf, the tram runs on French territory. On this section, there is one single station: Leymen. The Birsigtalbahn reached the village - at that time part of Germany - with the extension of 1910. Later, in 1919 Leymen together with Alsace was assigned to France.

In 2006, BLT and BVB (Basler Verkehrs-Betriebe) decided to order 60 Tango trams from Stadler. The first vehicle was ready in 2008, followed by 3 other trams until February 2009. The four prototypes were tested until autumn of 2009 in the scheduled traffic, then at the end of the test period, BLT ordered 15 trams from Stadler. These 15 vehicles are expected to arrive in Basel in 2011-2012. The Tango trams are 45 m long, with 75 % low-floor space. They can carry 94 seated and 182 standing passengers at a maximum speed of 80 km/h.