This article reports on a systematic review of the evidence concerning the impact of citizenship education, specifically focusing on the effect of different teaching activities on a range of active citizenship outcomes. It provides a narrative synthesis of 109 articles in peer reviewed journals, representing a wide range of methodological approaches. The review was undertaken for a teacher audience and the research team identified four themes with practical implications. First, we discuss the significance of school ethos and distinguish between distinctive aspects of ethos in the literature including relationships between students and teachers, values and behaviours. Second, we explore some of the characteristics of successful projects, including detailed consideration of the type of projects selected for action by young people, the role of teachers, and the duration of projects. This discussion suggests that, whilst full project cycles (involving students identifying and researching areas for action and devising, implementing and reviewing action plans) are valuable, there is also evidence to suggest that short, partial projects may be easier to implement and still secure comparable benefits. Third, we consider the evidence about whether and how citizenship education can have some compensatory effect, closing the civic gap between different groups of young people. In the fourth theme we consider the wide range of teaching strategies which have been demonstrated to have some success in practice.