The present paper advances knowledge of the drivers of firms' proactive environmental strategies. In particular, it explores the relationship between different corporate ownership structures and firms' green proactivity, in order to see whether some types of shareholder act as a stimulating driver for firms' proactive environmental behaviors. The study examines the explanatory power of corporate governance issues, such as a firm's ownership structure, as potential determinants of companies' environmental proactivity. Attention is focused on the European firms included into the Carbon Disclosure Project questionnaire 2012. The results show that ownership structure matters in firms' environmental proactivity. In particular, firms with a higher percentage of state ownership present superior green proactivity, while ownership concentration appears negatively related to proactive environmental strategy. The paper offers theoretical and practical implications. It focuses attention on a still underdeveloped research area, namely organizations and their relationship with the natural environment, including corporate ownership as a driver of a company's proactive environmental strategy. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment