This study looks at the dynamics of independence and accountability of national-level regulatory agencies. The model of the independent regulator has diffused across sectors and countries. Yet although this model is widely regarded as appropriate, the insulation of regulators from the electoral process raises questions of democratic accountability. To deal with this question, policy-makers introduce a range of statutory provisions for accountability. Thus, higher degrees of operational independence may, in principle, be compensated by higher degrees of accountability. In practice, though, we do not know how formal independence and accountability are related. This study seeks to explore the relationship between the two, using new data on the statutory provisions which apply to regulatory agencies operating in seven sectors in 24 established democracies. The concepts of independence and accountability are defined and operationalised, aggregate measures of the concepts are constructed, and the empirical relationship between the concepts is assessed.