The Constitutional Court decides the legality of treaties and the constitutionality of laws and decrees passed at the federal, provincial, and local levels. Cases involving courts and administrative agencies or the Administrative Court and the Constitutional Court are heard in the Constitutional Court. Individuals can present cases to the court if they believe a decision of an administrative agency has violated their constitutional rights. Monetary claims against the state, provinces, administrative districts, or local communities that cannot be settled by a regular court or an administrative agency are brought to the Constitutional Court, as are claims regarding disputed elections. The court also decides questions of impeachment and hears cases charging the president with breaking a constitutional law or cases charging members of federal or provincial governments with breaking a law.

The court is composed of a president, vice president, twelve judges, and six alternates. The federal president, on recommendations from the cabinet, appoints the court's president, vice president, six judges, and three alternates. The federal president appoints six additional judges and three more alternates based on nominations from the Nationalrat (for three judges and two alternates) and the Bundesrat (for three judges and one alternate). The constitution requires that three judges and two alternates of the court, which sits in Vienna, live outside the city. The president of the court chairs its meetings and decides on the assignment of cases to individual judges. He does not have voting rights, however. Cases are heard by five, nine, or all thirteen of the judges and are decided by majority vote.

The selection of judges for the Constitutional Court has been controlled by the ÖVP and the SPÖ. The two parties have applied the principle of Proporz to filling vacancies on the court. Between 1945 and 1970, the ÖVP was the larger of the two parties in terms of parliamentary strength, and it controlled seven of the judgeships with voting rights the SPÖ controlled six of the judgeships. Beginning in 1970, the ratio was reversed when the SPÖ gained more seats in the parliament than the ÖVP.

Data as of December 1993