Starting from Bangkok Station, the Northeastern Line passes through Ayutthaya, Saraburi, Nakhon Ratchasima, Buriram, Surin, Sisaket and ends at Ubon Ratchathani (575km).

At Kaeng Khoi Junction Station (125km), there is a branch line through Saraburi, Lopburi and Chaiyaphum provinces to Bua Yai Junction Station (346km) on the line to Nong Khai.

At Thanon Chira Junction Station (266km), there is a branch line to Khon Kaen (450km), Udon Thani (569km) and Nong Khai (624km).