In 2003, the International Conflict Resolution Centre at the University of Melbourne, Australia, produced a primary school teaching manual for UNESCO Vietnam. The finished manual included lesson plans and materials for a five year, 50 lesson peace education course. The manual is one of the first examples of a systematic core national curriculum in peace education worldwide. Development of the Teaching Manual posed a number of challenges including differences in language, culture, government and education system. To meet these challenges, a participatory action research approach was central in the project's development and curriculum design. This case study is offered as a model for effective cross-cultural curriculum development of peace education materials. In particular, the use of games and reflective materials and the use of UNESCO's peace keys are outlined as innovative outcomes of the project.