It has a surface area of 178.5 km² and a maximum depth of 337 m.[9] The Lake's National Park status has ensured protection to its environment.

Even though the lake has a regulating effect, it is subject to water level variations that may exceed 3 m and reflect in the discharge at the outflow.

The lake may appear green, blue or silver depending on the cloud cover and weather on a given day.

[11] However, later practice reverted to the name given by Jesuit missionaries, Todos los Santos Lake.

The mountains include Osorno volcano in the west, the Puntiagudo to the north, and the Tronador to the east.