Currently there are many optimistic expectations for the new and still little understood technology “blockchain”. This paper takes a critical stance and analyses the potential of blockchains in supply chain management (SCM). In the context of SCM, the application of blockchains promises transparency and traceability. It turns out that the expectations are not always met, because blockchains lose many of their positive characteristics when used in SCM. This is mainly due to the fact that both a digital level (information) and a physical level (goods) exist. In the original application area of blockchains - cryptocurrencies - only the digital level exists. In any case, blockchain technology (as well as every other technology) will not be able to solve the coordination problems within supply chain networks without the individual companies being willing to implement expensive IT interfaces and share their information.