Background: UK government policy views collaboration with outstanding schools as a way of helping apparently less successful schools to close the attainment gap. However, there has been little debate about criteria for defining a school's success or failure. Moreover it is unclear which aspects of outstanding schools could readily transfer to other schools. These questions applied when EducAid, an NGO with schools for disadvantaged children in Sierra Leone, was asked to provide a programme of workshops for teachers in neighbouring schools. Aims: (i) To establish whether EducAid's results justified agreeing to the request; (ii) To identify key features of EducAid schools that could be transferable to neighbouring schools; (iii) To propose key features of an evaluation. Methods: Collection of national and local data and analysis of key features of EducAid schools that could, and could not, transfer to other schools. Findings: The limited available data supported a decision that EducAid schools should offer workshops for other schools. Key components of the programme are identified, with a design including an ambitious evaluation framework. Conclusions: To our knowledge, this is the first time that teachers in successful schools have been asked to provide a structured programme of workshops for teachers in neighbouring schools. Discussion focuses on the challenge of inter-school collaboration in a low-income country. This includes the tension between the models of pedagogy and interpersonal relations promoted in the CPD and the constraints imposed by the public examination system.