This study examines the interaction between the effectiveness of audit committee and external audit functions to mitigate the earnings management in the Tunisian companies before and after financial security law adoption. Using 261 firm-year observations during the period 2001-2009, our results document a substitute effect between the presence of Big four auditor and effective audit committee to reducing the discretionary accruals in the Pre-law n° 2005-96 periods. We also find a link of complementary between the score of effectiveness of audit committee and industry specialist auditor to constrain earnings management. Finally, our findings show a complementary relation between the effectiveness of audit committee and audit tenure, after the passage of law n° 2005-96
Keywords: Accruals, Audit Committee, Audit Quality, Law N° 2005-96
