Thailand's rail network radiates from Bangkok, which is why every journey on this page starts there. The Northern Line reaches Chiang Mai in about ten hours. The Northeastern Line splits toward Nong Khai and Ubon Ratchathani. The Southern Line runs down through Hua Hin, Chumphon and Surat Thani to Yala — close to sixteen and a half hours end to end.
Two decisions come before booking. The first is which station you leave from. Most long-distance services now depart from Krung Thep Aphiwat Central Terminal, and Hua Lamphong and Thonburi are separate stations rather than older names for it. Go by the station printed on your ticket. The second is what you book: a seat, a berth in a sleeper carriage — upper or lower — or a private cabin. The price gap between them is smaller than the comfort gap.
No train reaches the islands. SRT takes you to the mainland and a road transfer plus a ferry does the rest: Koh Tao via Chumphon or Surat Thani, Koh Samui and Koh Phangan through the piers near Surat Thani. The guides below take each of these decisions one at a time.