Introduction: In this study, we use Porter’ s (1980) organizational strategy typology to examine the impact of leadership cost, as one of the trading strategies, and market competition on real earnings management. By doing so, we provide evidence on whether cost leadership strategy is one of the underlying determinants of earnings management. Furthermore, we examine the interactions between cost leadership strategy and market competition and its impact on earnings management, providing evidence on whether an external contributing factor such as market competition may have incremental influence over earnings management through its impact on an internal factor such as business strategy. Business strategy, as an important factor affecting internal governance mechanism (Miles and Snow, 1978, 2003; Ittner et al., 1997) has received little attention on its impacts upon earnings management. Our study, for the first time, attempts to explore whether cost leadership strategy maybe an underlying determinant of earnings management. . . .