In democratic systems, the right to inquiry and investigation has been recognized as a form of legislative supervisory function on other branches of power, especially on the executive branch. Regardless of the type of parliamentary system (unicameral or bicameral), there is a consensus among most of the parliaments in accepting this right, but there are differences in its implementation. By identifying this right as a collective right of the parliament, they have been given special legal powers to use it in its realization. Non-compliance of individuals, both natural and legal, to these powers can lead to the implementation of the sanctions. Nevertheless, what is particularly noteworthy in the results of the work of the parliamentary inquiry body is the guarantee of the implementation of this supervisory function, which is often political and has no direct legal effect. In this research, which was conducted in a descriptive-analytical way and based on library sources, the authors show that the parliament in Iran faces more shortcomings in comparison to many countries, both in terms of inclusion and in terms of inquiry powers. In order to make this dynamic monitoring tool more suitable, it is necessary to amend the law of the internal regulations of the Islamic Consultative Assembly and identify more legal powers in performing the task of inquiry in related laws, as well as providing clear and accurate interpretations of the scope of this constitutional right according to the interpretations of the competent legal authorities