Given the performativity culture of English schools (Ball, 2004), it is worth asking what impact the policy of autonomy adopted and promoted by central government since the 1988 Education Reform Act has had on students’ learning outcomes. UK-based research addressing this issue is limited, however data from large-scale international assessment studies can shed some light as they enable the effects of country-level differences in autonomy policies to become apparent. Findings from studies such as PISA and TIMMS reported by Wossmann et al (2007), and Maslowski et al (2007) as well as commissioning bodies (OECD, 2007) will be subjected to critique. This paper will reveal limitations of the claims that have been made that autonomy enhances student performance in terms of the methodological approaches taken, as well as conflicting messages in the data presented. The second part of the paper will report emerging findings of the link between autonomy (based on a composite measure related to finance, employment policies, teaching arrangements, contractual conditions, accountability and administration decisions) and performance outcomes in the five case study schools. Although these empirical findings are limited by the scope of the comparative case study, it will be argued that the wider range of indicators included in this analysis engenders a more sophisticated understanding of the relationship between autonomy and learning outcomes.