[1] The line was opened in stages between 1910 and 1927 (with construction being delayed by the onset of the First World War) to service the booming timber industry as well as rural and fruit-growing establishments between the two termini.

Pinjarra and Narrogin are located on the Western Australian Government Railways' South Western and Great Southern main lines respectively, and as such the Pinjarra to Narrogin railway provided an important link between the two, providing a rail transport link to towns and mills along the way, such as Dwellingup and Boddington, both of which continue to be significant settlements in the region.

[7] The final section Dwarda to Narrogin was not awarded for construction to the PWD until 24 July 1925, and officially opened on 18 September 1926.

[3] In 1954, the state government of Western Australia had compiled a list of loss-making railway operations, of which the Pinjarra to Narrogin line was one.

This act affected a number of Western Australian railways, officially closing 13 lines in the state.