The European Impact Assessment (IA) has been in place for the last 10 years. By and large, this is deemed best practice within the context of the various experiences related to 'Better Regulation' which have flourished in the last years or so internationally. The IA is based on common guidelines for all Commission services; the sharing of methodologies for the impact analysis of the proposals; various forms of cooperation among General Directorates. In this article it is argued that the IA has supported the strengthening of a coordination role of the General Secretariat and a more integrated decision making process within Directorates. These outcomes have been favoured by a bundle of mechanisms triggered by the design of the procedure.