Our inferences are based on comparisons of accounting quality metrics for a broad sample of firms in 21 countries that adopted IAS between 1994 and 2003. In particular, we compare accounting quality metrics for firms that apply IAS to those for a matched sample of non-U.S. firms that do not in the period after the IAS firms adopt IAS. We generally find that IAS firms ' ave higher accounting quality than firms that do not apply IAS. Differences in accounting quality between the two groups of firms in the period before the IAS firms adopt IAS do not account for the postadoption differences. We also compare accounting quality metrics for IAS firms in the periods before and after they adopt IAS. We generally find that IAS firms evidence an improvement in accounting quality between the pre- and postadoption periods.