In many countries, advisory councils are the most common participatory institution in which public administration interacts with civil society around environmental issues. Nevertheless, our knowledge about them is quite limited. The main goal of this article is to show the di erencesthey present with advisory councils in other policy areas in three main aspects: who participates, how they work, and which are their outputs. These diferences are especially important because they emerge again regarding their participants' opinions and satisfaction. We adopt a quantitativeperspective in order to analyze this reality in Spain, a country where advisory councils are widespread and highly institutionalized at national, regional and local levels. After developing a mapping of 2013 existing advisory councils, we selected a sample of 55 in three policy areas. The data collectedincluded their formal rules, composition, website characteristics and a survey to 501 participants. This set of evidence shows that environmental councils are more poorly designed, and that this is consequential since it is related with more negative opinions among their members and to a larger degree of polarization in their perceptions.