The European Union has recently enacted the Conflict Minerals Regulation, introducing new transparency requirements for importers of tantalum, tin, tungsten and gold from conflict-affected regions. Similar legislation has previously been enacted in the United States. The purpose of the new transparency requirements in both jurisdictions is to cut off funding for armed groups in confl ict areas and thus reduce the suffering of the civil population, with particular reference to the situation in the Democratic Republic of the Congo. The criticism of the legislation centers on the costs to companies in the minerals supply chain. In this article it is argued that the costs to companies subject to the transparency requirements can be minimized with carefully crafted legislation. It is also concluded that progress in achieving the humanitarian objectives of the legislation is slower than expected, mainly due to the lack of participation in the transparency efforts by all actors in the supply chain. Successful transparency regulation has to be supported by a multitude of actors in the international community. Also, mineral supply chain transparency regulation in itself is unlikely to solve armed conflicts in resource-rich but poor countries. Such legislation only provides for one component in a multi-level approach including legislative, economic and political efforts by the international community.