No / This article observes separately and jointly the impact of international financial reporting standards (IFRS) and/or board of directors’ independence on accounting conservatism in FTSE 100 nonfinancial firms between 2002 and 2007. Using Givoly and Hayn’s (2000) accrual-based measure of accounting conservatism, we found a reduction in conservatism after the mandatory adoption of IFRS, and, also, that board of directors’ independence improved accounting conservatism. Moreover, IFRS and board of directors’ independence had a complementary impact on accounting conservatism since the role of independent directors was not observable prior to the mandatory adoption of IFRS. Our results suggest that, after the mandatory adoption of IFRS, independent directors are likely to put significantly more pressure on the management to practice more accounting conservatism.