The article deals with legal regulation of parliamentary oversight of special services in Poland in the context of general constitutional regulations concerning the functioning of parliament. The forms and scope of potential oversight to be exercised over the services are subject of diverse opinions and considerable controversies, resulting from the collision of different constitutional principles and values. These includes above all the division and balance of powers as well as Government's accountability to parliament, and also the principles of efficiency and openness of the operation of Government. Particular problems are caused by the fact that, the functioning of the special services is secret in nature and is closely linked to the centre of political authority. Therefore, there is a trend to exclude parliament and parliamentary opposition from dealing with this issue. Parliamentary oversight is also hindered by attempts by the special services to become independent. The following four models of oversight and supervision of the special services are distinguished: internal, political (governmental), parliamentary and social. In the Polish circumstances, we should add a judicial model and oversight performed by the constitutional organs of state audit and legal protection. In Poland, parliamentary oversight has no well-established tradition. In 1995, following previous attempts, a Special Services Committee was established as a permanent auxiliary organ of the Sejm. The establishing of the Committee initiated the process of development of a new model of supervision of the special services and coordination of their activities. The article also presents in detail the following issues: membership of the Special Services Committee (no more than 9 members), access of their members to information containing legally protected secrets and the scope of its tasks and responsibilities (three 'areas' are distinguished in this context: legislative, oversight and opinion-making). In the summary, the author opts for changes to be introduced in the legal system, particularly to implement a statutory principle which extend the scope of oversight exercised by the Committee to all elements of special services (today only some of them are subject to such oversight) and refusal to submit information is subject to external oversight.