Plimmerton is a late example of a standard island-platform station. Symmetrical along its main axis, the building is rectangular in plan with doors and windows to platform elevations and lapped weatherboard cladding. At present all windows are boarded up to prevent vandalism. The gabled corrugated-iron roof incorporates another gable perpendicular to the main orientation of the building. The verandah, identical on both elevations, is supported by old 70lb rail. As built, it was one room wide, containing, from north to south, men’s and ladies’ toilets, ladies’ waiting room, bookstall, general waiting room, office and booking office, and a store room. The internal layout includes an original emergency signal panel, and the building has been restored and modified to accommodate a Mac's Track model railway shop.
Plimmerton’s first station was built in 1886 by the Wellington and Manawatu Railway. It survived with additions until duplication of the line in 1940 led to the construction of a new station: like the similar but smaller Tawa, which was rebuilt in 2013, it is an island-platform station. The plan was approved in 1939 and work began. By February 1940 the new station was in use, but it was not completed until September that year, when the old building was demolished. The line was electrified as far north as Paekakariki in June 1940, and an intensive suburban service was introduced. The station closed to freight traffic on 21 January 1989 and later that year it was proposed to lease out part of the yard, now occupied by Mainline Steam’s locomotive depot. In 2008 the subway was extended through to the eastern side of the line. The verandahs, platform and subway are well used by passengers on Metlink's Kapiti Line, and the building by waiting passengers and shop customers.