This thesis is a quantitative review of research on cooperative learning in secondary mathematics. It uses meta analytic procedures for quantitatively synthesising the findings from empirical studies conducted in the field. Results from the analysis demonstrate that cooperative learning has an overall positive effect in the cognitive domain as well as the social and affective domain in secondary mathematics. The presence or absence of equivalence between experimental and control conditions, duration of the study, form of cooperative learning method used, source of the outcome, and grade level of the students were the qualities which significantly moderated the effects. Results of this study also indicate that there is still scope for further research into cooperative learning in secondary mathematics classrooms.