How does owner identity affect environmental management system (EMS)adoption by business group affiliates? While current research on EMS adoptionis mostly focused on stand-alone Western firms, a marked uptake of adoptionhas unfolded in Eastern countries such as China, where business groupaffiliates are the dominant organizational form. This stark contrast betweencorporate interest and research attention has left a clear lacuna in ourunderstanding of how systems that can reduce environmental impact diffuseacross industrial settings. We argue that state, family, and foreign ownersof affiliated firms show distinct propensities to adopt an EMS, owing todifferences in legitimacy needs, ownership competencies, and group-levelpreferences to engage in systematic environmental practices. Logisticregressions based on data from listed Chinese business group affiliatesbetween 2008 and 2019 show that state and family ownership negativelyinfluence the likelihood of EMS adoption, whereas foreign control has apositive effect. More intragroup transactions exacerbate the low adoptionpropensity of family-owned firms. Our study contributes to the literatures onbusiness groups and corporate environmentalism.