As the Kotka fortresses had been destroyed during the Crimean War and the islands of Kotkansaari and Hovinsaari fell out of military use, the Finnish state offered to lease out plots on the former for industrial use in 1868.

[2] Talks regarding the construction of a branch of the Riihimäki–Saint Petersburg railway to southern Kymenlaakso sprung up soon after the former's inauguration in September 1870.

The first mayor of the town of Kotka, Oskar Backmann, proposed in 1880 the building of a railway to Kotka to ease the logistical issues between the town's harbour and inland Finland, while the Diet of Finland debated the construction of a railway to Hillo or Nuottaniemi in Hamina.

By 1882, the Kotka option had gained the backing of the Railway Committees of both the Diet and Senate of Finland, and during the 1888 session of the Diet, the decision to build the Kouvola–Kotka railway was made; it was opened for provisional traffic with celebrations in the summer of 1890, and was officially inaugurated in the fall.

[6] On the Kouvola–Kotka line, these services call in Myllykoski, Inkeroinen, Tavastila, Kymi, Kyminlinna, Paimenportti and Kotka.