This article reviews empirical research on the effects of student participation in school decision-making processes. Out of 3102 searched citations, a total of 32 publications met the inclusion criteria. The qualitative analyses employed in this review yielded a typology of student participation, a categorisation of the diverse effects of student participation and an overview of the quality and quantity of related research (available evidence). We found moderate evidence of positive effects of student participation on life skills, self-esteem and social status, democratic skills and citizenship, student-adult relationships and school ethos. We found limited evidence of positive effects on academic achievement, facilities, rules or policies, and health; we also found low levels of evidence of negative effects. We did not find sufficient research on the positive effects of student participation on peer relationships or on effects on teachers. Different forms of student participation seem to have different effects, but first and foremost, this review indicates a need for more comprehensive high quality research. (Contains 2 tables and 2 figures.)