In 1894, the Danish engineer Aage Westenholz (1859–1935),[1] uncle of the writer Karen Blixen, was given the concession to build a route from Bangkok to Phetchaburi.

After the Thai state had repurchased the West timber concession, the Royal Railway Department (RRD) in the Ministry of Public Works planned a route, under Karl Bethge from the Krupp Company to Phetchaburi.

The building was designed in the style of brick expressionism by the German architect Karl Döhring, engineer with the Royal State Railways of Siam.

On 1 April 1903, traffic on the first completed section between Thonburi and Phetchaburi was operated with makeshift carriages, as delivery of a significant portion of the rail vehicles was delayed.

When these had arrived, the official opening was held on 19 June 1903 by King Chulalongkorn (Rama V.) On 1 July 1918, trains were able to operate from Thon Buri Railway station to Malaysia via Padang Besar.

Long-distance trips were interrupted for overnight stays with the Royal State Railways of Siam providing hotels at major train stations.

This was not only technically reasonable, because it provided a uniform administration for each of the two gauges operated by the state, but also a political balancing act of Thailand, which until 1917 was neutral in the First World War.

The northern RRD worked under the German director Karl Bethgen, the southern under the British Henry Gittens, whose countries of origin were now enemies of the war.

After Thailand's entry into the war on the British and French sides on July 22, 1917, the connection of the Malay and the Thai railway network received high priority.

In 2003, the terminus of the line westward to the previous station Bangkok Noi, was relocated and the vacated railway area was utilised for the extension of Siriraj Hospital.