In this paper, the authors outline a project that they initiated in a mainstream primary school to promote cooperative learning throughout the school by using a lesson process to teach social and emotional skills. In doing so they provide a brief overview including research of the benefits of cooperative learning, followed by a description of how the project developed. Some evidence is presented from a variety of sources examining the impact of the project. The paper concludes by examining the factors that helped to establish cooperative learning practices in the school and by suggesting the kinds of data that may be useful to gather in the development of the project in other schools. (Contains 1 table.)