The aim of this paper is to discuss how regional parliaments fit into the democratic organization of the multilevel polity of the EU. It seeks to further our understanding of the different levels of activity of different regional parliaments. For this purpose the first part studies the opportunities available to regional parliaments for EU affairs scrutiny at different levels (i.e. control of their own government, control of the European institutions etc.). It will present an overview of how regional parliaments can be involved in EU politics, discussing the various dimensions of legislative - executive relations, both formal and informal. It will make a distinction between within-level scrutiny (regional parliament - regional government) and multilevel scrutiny (across the regional, national and European level). In this context, the paper also discusses the specific challenges faced by regional parliaments with an interest in EU affairs, such as the difficulty of controlling the Council of Ministers.