[1] The lake is first mentioned in a border description of the diocese of Freising from the years 1073/78 as Planse, other early names include; Please , Plense and Plase.

Duke Siegmund and his successor, Emperor Maximilian I, tried to get their hands on the best fishing waters in the country.

However, the Stams monastery insisted on its rights and was granted a limited fishing right, which was confirmed in a contract of 1631 by Archduke Leopold V.[3] In 1902, the Plansee power plant was put into operation, and in 1908 the canal to the Heiterwanger See was built, and was eventually widened in 1951.

Thanks to the greater generation of electricity brought about by Hermann Stern who succeeded in 1922 in persuading Paul Schwarzkopf to found the Plansee metal works.

During World War II, a subcamp of Dachau concentration camp for men and women was located here.