This article discusses the relation between a theoretical concept of oversight powers of the Sejm and constitutional limitations imposed on the legislature in relation to shaping the structure of public authorities. The subject of this analysis includes answers to the following questions:- Whether the scope of parliamentary oversight is entirely determined by the provisions of the basic law, or does the constitution specify only major functions of public authority which are subject to parliamentary oversight while the legislature has the discretion to extend the scope of such oversight to include extra-constitutional aspects of such control? - Whether the legislature, upon creating extra-constitutional organs of the State, may place them outside the area of the oversight exercised by the Sejm? - Whether parliamentary oversight cover the entirety of the State apparatus, except for those organs whose independence is guaranteed, or whether the scope of oversight exercised by the Sejm is limited only to the activities of the Council of Ministers? The concept of 'broad' oversight function of the Sejm, understood as the right of this legislative body to be informed about the activity of public authorities and institutions, is coherent with both the standpoint in favour of the overall nature of the constitutional regulation of the sphere of State authority and the opinion that the basic law regulates only fundamental institution of the system of government, and leave discretion to the ordinary legislator to define extra-constitutional functions of the State and to delegate them to extra-constitutional organs. Another concept of oversight function of the Sejm assumes that Article 95(2) of the Constitution delimits the scope and nature of oversight exercised by it. As a result, the scope of oversight by the Sejm corresponds to the scope of activity of the Council of Ministers, which covers the affairs of State not reserved to other State organs or local government (Article 146 paragraph 2 of the Constitution). This provision functions as a presumption of competence, which complements the constitutional regulation in relation to actions undertaken by State within its ruling capacity. Without explicit constitutional authorization, the legislature may not reduce the competence of the Council of ministers, since this would contradict the principle of superiority of the basic law. Such a conduct would also lead do diminishing oversight functions of the Sejm. Therefore, a 'narrow' concept of oversight function must assume that the scope of constitutional regulation has an overall nature and includes all aspects of State control and that it determines an organizational structure of the entire apparatus of power. The oversight function of the Sejm, within the above-mentioned meaning, seems not to be reconciled to the practice of creation of extra-constitutional organs of the State which perform extra-constitutional functions. Such organs, existing outside the organizational system of the Council of Ministers, would not be subject to oversight by the Sejm. .