The 124-square-kilometre (48 sq mi) municipality encompassed the land to the east and west surrounding the Vatsfjorden and the lake Vatsvatnet.

The majority of Vats (population: 1,128) was merged with parts of Imsland, Skjold, and Vikedal, as well as all of Sandeid to form the new municipality of Vindafjord.

On the same day, the Breidal and Stølsvik farms on the south side of the Yrkefjorden (population: 16) became a part of Tysvær municipality.

The name comes from the dative case of the word vatn which means "water", likely referring to the lake know known as Vatsvatnet.

[6] The municipal council (Herredsstyre) of Vats was made up of 15 representatives that were elected to four year terms.