Globally, family firms are the dominant organizational form. Family involvement in business and unique family dynamics impacts organizational strategy and performance. However, family control of business has rarely been adopted as a discriminating variable in the organizations and the natural environment (ONE) research field. Drawing on the theory of planned behavior we develop a conceptual framework of the drivers of proactive environmental strategy (PES) in family firms. We argue that family involvement in business influences the attitudes, subjective norms, and perceived behavioral control of a firm’s dominant coalition. Together these factors determine the extent of the dominant coalition’s intentions to undertake PES. Further, family firms with lower levels of relationship conflict within the controlling family will be more successful in translating the dominant coalition’s intentions to allocate resources for the pursuit of PES. Research implications of the theory are discussed.