Bosnia and Herzegovina consists of Federation of Bosnia and Herzegovina (FBiH), Republika Srpska (RS), and Brčko District (BD). The Federation of Bosnia and Herzegovina covers some 51% of Bosnia and Herzegovina's total area, while Republika Srpska covers around 49%. The entities, based largely on the territories held by the two warring sides at the time. The Brcko district in the north of the country was created in 2000 out of land from both entities. It officially belongs to both, but is governed by neither, and functions under a decentralized system of local government. The Brčko district has been praised for maintaining a multiethnic population and a level of prosperity significantly above the national average.

Bosnia is home to three ethnic "constituent peoples": Bosniaks, Serbs and Croats. Tensions between the three constitutional peoples remain high and often provoke political disagreements. According to the 1991 census, Bosnia and Herzegovina had a population of 4,377,033. Ethnically, 1,902,956 (43%) were Bosniak, 1,366,104 (31%) Serbs, and 760,852 (17%) Croats, with 242,682 (6%) Yugoslavs. The remaining 2% of the population - numbering 104,439 - consisted of various other ethnicities. According to 2000 data from the CIA World Factbook, Bosnia's largest ethnic groups are Bosniaks (48%), Serbs (37%) and Croats (14%).[42] There is a strong correlation between ethnic identity and religion in Bosnia and Herzegovina: Muslims constitute 45% of the population, Serb Orthodox 36%, Roman Catholics 15%, and other groups, including Jews and Protestants, 4%.