Purpose: This paper aims to compare the influence of different legal systems on corporate sustainability management practices. Against the background of growing internationalization of business activities, it additionally considers whether internationalization allows companies to circumvent the influence of national authorities. Design/methodology/approach: Three legal systems are compared using regression analyses of more than 200 large corporations in five countries: common law (USA and Australia), German code law (Germany) and French code law (France and Spain). Findings: The impact of national and international authorities is found to be strongest in French code law countries. In addition, the influence of international authorities is stronger for corporations with higher shares of international sales. For both national and international authorities, the degree of internationalization is found to moderate the influence of the legal system on corporate sustainability practices. Practical implications: The legal system in place influences the relative effectiveness of national and international authorities over company sustainability practices and needs to be taken into account in policymaking. To be effective, international authorities need to work with or substitute for national authorities in promoting corporate sustainability practices in countries depending on their legal systems. Originality/value: This research applies and quantitatively tests La Porta’s (1998) framework on legal systems in the new context of corporate sustainability. © 2017, © Emerald Publishing Limited