Disclosure of income, assets and conflicts of interest can serve as powerful public accountability tools to draw attention to the abuse of public office, help prosecute corrupt offenders and create a culture of scrutiny in the public sector that deters corruption. Based on data of the World Bank’s Public Accountability Mechanisms initiative, we present the first indicator that captures a country’s financial disclosure in-law effort. By employing different panel data model specifications, we use this indicator to measure how the introduction of comprehensive financial disclosure systems impacted national corruption levels for 91 countries between 1996 and 2012. We present robust results that provide tentative evidence for a positive and significant relationship between a country’s capacity to control for corruption and the expansion of financial disclosure legislation for the years following the enactment.