Eidfjord existed as a municipality from 1891 until 1964 when a major municipal merger took place as a result of municipal reform in Norway due to the Schei Committee. The municipality of Eidfjord (population: 983), most of the municipality of Kinsarvik (population: 1,513), and the municipality of Ullensvang (population: 2,358) were all merged into one large municipality that was named Ullensvang. This merger was not well-liked by the population of Eidsfjord, and so on 1 January 1977, part of the merger was undone, and the area of the "old" Eidfjord municipality (population: 1,223) was separated to form its own municipality once again.