This paper describes how critical realism was operationalized to provide an explanatory framework for a small-scale qualitative study in the field of teacher education in a sub-Saharan African context. Critical realism combines a realist ontology (there is something to find out about) with a relativistic epistemology (different people will come to know different things in different ways). An attraction of this approach is that it seeks to explain observed phenomena through processes of inference, thus providing the opportunity to make changes for the better in the situation under investigation. The stratified view of reality provided a framework for the analysis of data, which led to the identification of two underlying causal mechanisms and new understandings of teacher education in sub-Saharan Africa. The approach is not without challenges, including the potentially intrusive nature of the enquiry and the positioning of the researchers. Despite these challenges, the evidence from this study is that the approach has the potential to provide new insights which have informed on-going international development projects in teacher education in sub-Saharan Africa.