This study aims to examine the effects of strategic management accounting on firm performance of finance businesses in Thailand. Strategic management accounting comprises of environmental scanning, competitor orientation and forward-looking information. In this study, 175 finance businesses in Thailand are the samples of the study. A mail survey procedure was used for data collection. The hierarchical multiple regression analysis is employed to test the research relationships. Firstly, environmental scanning positively affects operational excellence, organizational effectiveness and firm performance. Secondly, competitor orientation is positively related to managerial efficiency and organizational effectiveness. Thirdly, forward-looking information has a positive influence on operational excellence, managerial efficiency, organizational effectiveness, and firm performance. In addition, operational excellence, managerial efficiency and organizational effectiveness have positive impact on firm performance. Finally, to verify the mediating effects, operational excellence, managerial efficiency and organizational effectiveness are the mediators of the research relationships. This study confirms that all dimensions of strategic management accounting play a significant role in determining business outcome as being congruent with the theory of resourcebased views of the firms. Executives of firms need to provide valuable resources and capabilities to support the strategic management accounting implementation in order to achieve good business outcome in highly competitive environments.