This study examines environmental management practices of 1690 family and nonfamily firms from 29 countries and 19 industrial sectors over an 8-year period. We show that the family effect on firm environmental management practices ranges substantially, from extremely negative to no effect at all. Moreover, the magnitude of the effect depends on the type of firm, the industrial context, the type of economy, and the stages of the business cycle. This study offers a novel understanding of the extreme heterogeneity of environmental management practices of family businesses and serves as a springboard for future research aiming to better understand the environmental strategies of publicly traded firms with concentrated ownership structures. It also provides important and novel evidence for policymakers, investors, and business owners, particularly for firms with different ownership and management structures.