The political environment where a firm operates can impose several challenges to its performance such as new taxes or legislation that will incentivize their engagement on Corporate Political Activities (CPA). These activities target political actors and intend to capture advantages or to avoid institutional risks in their own business environments. They can be deployed in the form of lobbying, campaign contributions, and litigation. The positive outcomes have been already documented in the literature, but most of them refer to the US environment. Taking into consideration that the institutional environment is essential for the deployment and outcomes of CPA, the main goal of this dissertation is to investigate CPA in the European Union level further using an empirical approach. Through three research projects related to lobbying and litigation in the EU, this dissertation explores the dynamics of CPA and how the institutional environment impacts on it. The first project examines the determinants of firms' access to the European Commission representatives. The second project studies the making of the wholesale roaming regulation to understand the deployment of lobbying strategies and their outcomes. The third project investigates the decision-making of the European Commission and the Court of the Justice in the processes of granting state aids in the European Union.