Integrated agencies supervising banks, nonbank financial institutions, and securities markets have been gaining popularity around the globe. Using a unique data set on compliance with international standards in 84 countries, we find that greater supervisory integration is associated with higher quality of insurance and securities supervision and greater consistency of supervision across sectors. Within the different forms of integration, we find some support for the “twin peaks” model that integrates supervision across sectors but separates business conduct and prudential supervision. We also find that whether supervision is located inside or outside the central bank has no significant relation to supervisory quality.