This study deals with relations between the courts of review of constitutionality of legal norms and the European Court of Justice in the field of preliminary rulings. This procedure, referred to inter alia in Article 234 of the Treaty establishing the European Community, empowers - and, in some circumstances, even obliges - national courts to apply to the ECJ for interpretation or assessment of validity of European law, if the answer is necessary to solve the matter in domestic proceedings. The discretion in determining whether a given body is a court in the sense of Article 234 of the Treaty belongs, according to the prevailing Community theory, to the ECJ. Nevertheless, in the opinion of some constitutional courts, such power should be vested in them. The Italian Constitutional Court explicitly held that it would not refer a matter for preliminary ruling. So far this been made only by two courts of review of constitutionality of legal norms: the Belgian Court of Arbitration and Austrian Constitutional Court. This does not however mean that asking such question does not constitute a point of interest of those courts. Due to their special status within national legal order, this problem deserves special attention.