This paper examines the relationships between environmental regulations, firms' innovation and private sustainability benefits using nine case studies of UK and Chinese firms. It aims to unravel the mechanisms by which a firm's environmental behaviour in improving its private benefits of sustainability is influenced by its relationship with the government, which primarily enacts regulations to maximise public sustainability benefits in the interests of society as a whole. The paper takes its cue from the Porter hypothesis to make some broad preliminary assumptions to inform the research design. A conceptual framework was developed through inductive case studies using template analysis. The results show that depending on firms' resources and capabilities, those that adopt a more dynamic approach to respond to environmental regulations innovatively and take a proactive approach to manage their environmental performance are generally better able to reap the private benefits of sustainability.