The entire 181.1-kilometre (112.5 mi) network[5] uses 1,000 mm (3 ft 3+3⁄8 in) narrow gauge rail tracks which have been owned by the Basque Government since their transferral from the Spanish government; the rail tracks and stations were part of the FEVE network until its transferral.

[7][8] These trains serve areas such as Txorierri, Busturialdea and Durangaldea; including towns such as Derio, Lezama, Amorebieta-Etxano, Gernika, Bermeo and Durango.

[10] There are also trains from San Sebastián to the coastal towns of Zarautz, Zumaia and Deba; and further inland to Elgoibar, Eibar and Ermua.

Euskotren Trena operates a fleet of 58 electric multiple units (EMU), all built by CAF.

The 900 and 950 series, the two train types currently operating, are similar but feature a different number of cars.

[14] The new rolling stock (900 and 950 series trains) is painted with the new Euskotren Trena livery, white with black contrast and blue and orange circles in the doors.