With a wide range of potential benefits – such as improved traceability, food safety, and environmental sustainability, as well as increased farmer income– blockchain has become an increasingly popular technology option for commodity value chains. Yet, there is little knowledge among agri-food professionals of how the technology works, and there is (still) limited evidence of the impact blockchain has on the efficiency, the transparency of transactions, and the costs and benefits this may have for smallholders in particular. Most agri-food stakeholders also lack a detailed understanding of which potential applications are most relevant and valuable to their needs, or in software terms, what is the right ‘use case’. This article provides a brief introduction to blockchain, give examples of its use in the agri-food sector and how it has benefited smallholders, provide some key questions for those that are thinking of investing in blockchain, and offer some further sources of information for those interested to dive deeper. The most up to date evidence of proven business cases and tangible developmental impacts are also considered.