The objective of this study is to investigate the effectiveness of Thai government export policy on manufacturing exports. A comprehensive empirical study was conducted at both the macro and micro levels. First, and following the lead of most previous studies, econometric models of total manufacturing exports and each branch of industry are tested by using multiple regression and time series analysis. Second, a survey of the perceptions of Thai businessmen of the present government export policy was conducted. This study reveals that the major economic determinants of manufactured exports are internal production and external demand factors. In addition, the export promotion policies of the Thai government have a significant impact on Thai manufacturing exports. All export incentive programs by Thai governmental agencies have been ranked as an important factor in contributing to exporters' success in manufacturing exports. Although the government export incentive is not perceived as a very important factor in the dramatic increase of manufacturing exports in Thailand, it still plays an important role in the swift success of Thai manufacturing exports. The credit assistance, tax exemption and rebate are the most favorable export incentive programs. However, improvement of the process and new incentive programs, i.e., financial institutions for exports, are still in demand. Ultimately, in order for any kind of export promotion policy to be effective, the government must consider the effects from both the demand and supply side. Since some industrial products depend heavily on demand, some on supply, an export promotion program suitable for some manufacturing products may be ineffective for other products.