While the literature on the effective management of business and natural environment interfaces is rich and growing, there are still two questions regarding which the literature has yet to reach a definitive conclusion: (1) what is the interactive effect between internal and external drivers on a proactive environmental strategy (PES)? and (2) does a PES influence firm's performance? Drawing on the resource-based view for the internal drivers’ perspective and institutional and legitimacy theories for the external drivers’ perspective, this study suggests that the effect of entrepreneurial orientation on a PES is moderated by the intensity of government regulations and customers’ sensitivity to environmental issues. The authors also examine the relationship between the PES and a firm's performance in terms of sales and profit growth. Implications are discussed regarding the role of a PES in achieving a competitive advantage in the marketplace.