The line unites three villages on opposite sides of the border, Strymon and Promachonas in Serres, Greece, and Kulata in Blagoevgrad, Bulgaria, and is entrance/exit to the Greek rail network from Bulgaria.

[3] the line consists of a single 1,435 mm (4 ft 8+1⁄2 in) standard gauge line with a total length of 14.5 km (9.0 mi), constructed of old superstructure materials (S33B rails and S33 metal sleepers).

There are two tunnels and five bridges between Strymon and Promachonas, and service is provided to two passenger stations.

[3] The southern terminus of the Strymon–Kulata railway is Strymon on a branch from the Thessaloniki–Alexandroupoli line.

(Until further notice, this train is replaced by a 14-kilometre-long (8.7 mi) bus service between Kulata on the Bulgarian side of the Greek border and Strymon on the Greek side is in operation, from where a train continues to Thessaloniki.)