The paper concerns reviews conducted by administrative courts of decisions issued by public administration authorities on the basis of their administrative discretion. The author presents decisions of the administrative law doctrine and case-law of administrative courts, with particular regard to the current views. The author reflects on admissibility of the review of discretionary decision. He indicates the differences and similarities between a constrained decision and a discretionary decision, and also answers the questions whether it is admissible to conduct the review of the discretionary decision by administrative courts on the basis of the criterion of expediency and it is possible that the court considers only the criterion of legality. According to the main conclusions of the paper, there are no differences between the constrained decision and discretionary decision in terms of the review by administrative courts; the criterion of expediency is permitted if it results from the regulations empowering the authority to issue discretionary decisions; it has also been observed that administrative courts increasingly expand the review capacity to ensure the compliance with law, so that any such review could also be used to verify the correctness of the discretionary decision which has been issued.