This study examines the impact of improvements in institutional oversight specifically for compliance with International Financial Reporting Standards on accrual quality in Europe. The sample comprises 9339 firm-year observations from a treatment sample of three European countries that had either non-existent or relatively weak institutional oversight systems at the start of the sample period 2006–2010 but improved oversight systems thereafter, and a benchmark sample of six other European countries that had institutional oversight systems from the start of this sample period. After controlling for legal system, rule of law and other variables, we find incremental improvement in accrual quality in the treatment sample relative to the benchmark sample from the pre-enforcement period 2006–2007 to the enforcement period 2008–2010. The results suggest that institutional oversight has an incrementally positive impact on accrual quality over and above that attributable to legal system, rule of law and other variables. The results are robust to different measures of accrual quality, alternative enforcement proxy and alternative samples.