Arbitration, despite being located outside the constitutionally defined judiciary, may turn out to be a significant complement to it. The applicable regulations allow, in exercise of the freedom of contract, to exclude the jurisdiction of state courts by an arbitration agreement in order to resolve the matter by an arbitration court. The possibility of resolving disputes in the framework of arbitration by granting arbitration courts the status of legal protection bodies is widely accepted. The Constitution of the Republic of Poland defines the principles guaranteeing citizens the right of access to a court and the autonomy of rights and freedoms — does the functioning of arbitration comply with the basic constitutional principles, in particular by the perceiving arbitration in terms of private courts and referring to the constitutionally guaranteed justice system? The answer is affirmative, taking into account that the state judiciary supplemented by arbitration is perceived as shaping a modern judicial area of justice.