Under the Finnish Constitution, "justice in civil, commercial and criminal matters is in the final instance administered by the Supreme Court".
The most important function of the Supreme Court is to establish judicial precedents in leading cases thus ensuring uniformity in the administration of justice by the lower courts. Decisions of courts of appeal and land courts, as well as certain decisions of the District Courts, Insurance Court and Market Court may be appealed against to the Supreme Court, provided that the Supreme Court grants leave to appeal.
The Supreme Court may annul final decisions of courts on the grounds provided in Chapter 31 of the Code of Judicial Procedure. The Court also handles complaints concerning errors in procedure. In some cases the Court may restore the right of appeal after the expiration of a specified period of time.
The Supreme Court gives advice to the President of the Republic in cases concerning his/her right to grant a pardon, and to the Ministry of Justice in cases concerning extradition. The Supreme Court may further provide legal opinions on Government Bills at different stages of the legislative process. The President of the Republic may consult the Court in respect of Bills passed by Parliament and Provincial Acts adopted by the Åland Legislative Assembly before ratifying them. The Supreme Court may also approach the Council of State on its own initiative, and propose enactment of a new Parliament Act or an amendment to an existing Act.