This article describes a project that developed collaborative relationships between science and mathematics education researchers in South Africa and the USA. Significant features of the collaboration included a Liaison Committee with members drawn from both countries, exchange visits for pre- and post-doctoral researchers between the two countries, and the establishment of Research Schools in South Africa. An historical overview of the project focuses on both its functioning and its evolving structure. Summaries of assessments of two of its activities and their outcomes point to the project's influence on building research capacity at individual, structural, and community levels. Two aspects of sustaining the project-funding and structures-are discussed.