In order to improve the protection of human rights and the environment in global value chains, Germany is currently discussing a due diligence act. The inclusion of human and environmental rights standards into the sphere of responsibility of globally operating companies offers the opportunity to achieve more sustainable forms of global business. Since national due diligence laws apply across the entire supply chain, the question of their compatibility with WTO-law arises. The violation of the principle of non-discrimination and possible grounds for justification must be evaluated in light of and against the background of developments of WTO case law on the protection of non-trade values. The present article argues that a due diligence act would generally be compatible with WTO law.