Most Slovenian railway lines were built during the Austro-Hungarian Empire.

Overview

1,000 mm (3 ft 3+3⁄8 in) gauge

• Ljubljana tram system; 18,5 km, 1901-1958

760 mm (2 ft 5+15⁄16 in) gauge

• Poljčane - Zreče; 20,8 km, closed.
• Piran tram system; 5 km 750 V DC electrified tram, 1907-1952
• Parenzana railway; Triest - Škofije - Sečovlje border - Poreč, 33 km, 1902-1935.

750 mm (2 ft 5+1⁄2 in) gauge

• Kobarid - Pojana border - Cividale del Friuli, 9 km, Società Veneta 1915-1932

620 mm (2 ft 13⁄32 in) gauge

• Postojna Cave railway in Postojna; 2,5 km double track, opened in 1872.^{[citation needed]}

600 mm (1 ft 11+5⁄8 in) gauge

• Brestanica to the north; 6 km, closed construction railway.