The largely fictitious plot is based on the building in 1942 of one of the railway bridges over the Mae Klong river—renamed Khwae Yai in the 1960s—at a place called Tha Ma Kham, 5 kilometres (3.1 mi) from the Thai town of Kanchanaburi.

An estimated 80,000 to 100,000 civilians also died in the course of the project, chiefly forced labour brought from Malaya and the Dutch East Indies, or conscripted in Siam (Thailand) and Burma (Myanmar).

Saito announces that the prisoners will be required to work on construction of a bridge over the River Kwai so that the railroad connection between Bangkok and Rangoon can be completed.

Construction of the bridge serves as a symbol of the preservation of professionalism and personal integrity to one prisoner, Colonel Nicholson, a proud perfectionist.

The incidents portrayed in the book are mostly fictional, and though it depicts bad conditions and suffering caused by the building of the Burma Railway and its bridges, the reality was appalling.

Julie Summers, in her book The Colonel of Tamarkan, writes that Pierre Boulle, who had been a prisoner of war in Thailand, created the fictional Nicholson character as an amalgam of his memories of collaborating French officers.

[3] Boulle outlined the psychological reasoning which led him to conceive the character of Nicholson in an interview which forms part of the 1969 BBC2 documentary "Return to the River Kwai" made by former POW John Coast.

Whereas Nicholson disapproves of acts of sabotage and other deliberate attempts to delay progress, Toosey encouraged this: termites were collected in large numbers to eat the wooden structures, and the concrete was badly mixed.

[6] After the film was released, the Thais faced a problem as thousands of tourists came to see the 'bridge over the River Kwai', but no such bridge existed due to Boulle's aforementioned misassumption.