This case study provides an overview of an ACIAR-funded project to minimise aflatoxin contamination in Indonesian and Australian peanuts through research, development and extension of on-farm and postharvest management practices. It details the motivation behind the project, which ran for five years from 2001 to 2006, and the main outputs and impacts it has or is expected to make. One of the important impacts of the project, noted in the case study, is the quantification of actual—and potential for—aflatoxin contamination throughout the peanut food chain, which has established a clear link between agriculture and human health. This presents compelling justification for further action from national and provincial governments to develop and implement appropriate policy measures to reduce its impact throughout the Indonesian community. At the same time, dissemination of information on aflatoxin incidence and its management, generated by the project, has led to significant adoption by research and extension agencies, as well as to the creation of a large extension network program. The lessons learned from this project are useful for future research on peanuts in Indonesia.