This study offers an in-depth look at the functioning of the policy making process by analyzing a crucial phase: the process of issue definition, also called framing. The study aims at understanding what are the factors that allow a technical institution to act as a political actor. The focus is on the Italian Environmental Agency, i.e. the Institute for Environmental Protection and Research (ISPRA). The results show that ISPRA is able to play a political role in the framing process only when issues are highly technical, and thanks to two strategies: adopting compromise during the formulation of its opinions, and maintaining informal links with decision makers. This contribution aims at opening a room for reflection on the importance of framing as a key element for the study and improvement of the policy process between governmental and non-governmental actors.