There is growing worldwide interest in Japanese lesson study as a model for professional learning, with large-scale adaptations of lesson study taking place in many countries. This paper describes how teachers and researchers collaborated in a lesson study project carried out in three Victorian schools. It describes Japanese lesson study and the typical structured problem-solving research lesson that forms the basis for lesson study; and discusses how the collaborative planning process and the resulting research lessons, together with the post-lesson discussions, provided teachers and researchers with the opportunity to collaborate in the research process.