• Corporate governance;
  • earnings management;
  • discretionary accruals

We test whether corporate governance mechanisms promoted by best practice codes are effective in constraining earnings manipulation for a Spanish sample of quoted companies during the period 1999–2001. In particular, we analyse the association between earnings management and two key aspects of corporate governance: board composition and the existence of board monitoring committees. Our results show that board composition significantly determines earnings manipulation practices. However, the main role in constraining such practices is not played by independent directors, as UK and US based research suggests, but by institutional directors. No correlation is found between the existence of an independent audit committee and earnings management measures. Finally, the existence and composition of a nomination committee affects the role of independent directors in constraining earnings manipulation.