Its first segment, linking Turku to Karis, was commissioned in 1895, and work began the following year.

The second part of the Rantarata, linking Karis to Helsinki, was approved in 1897 and opened for traffic in 1902–1903.

The track was built to primarily serve commuter traffic and was therefore laid out with many curves and as few tunnels and expensive earthworks as possible.

This resulted in a series of corrections and straightening of curves, a work which began in the 1910s and continued all the way to the 1990s.

Work to electrify the line to Uusikaupunki was scheduled to begin in 2019, leading to the possibility of passenger service being reinstated.