The development of bioethanol can bring about socio-economic and environmental impacts. To support the sustainability analysis of bioethanol development and the decision-making on bioethanol promotion in Thailand, this study aims at assessing the socio-economic and environmental effects of bioethanol production using recursive dynamic computable general equilibrium (CGE) modeling. The assessment is carried out based on the bioethanol production targets in Thailand's Alternative Energy Development Plan (AEDP) 2015, capturing cassava ethanol and molasses ethanol. Simulation scenarios are set up to incorporate the role of bioethanol support policies, such as tax reduction, production efficiency improvement, and widening the price gap between gasoline and gasohol, into the analysis. The results show that increasing bioethanol production together with improving the efficiency of feedstock cultivation is the most efficient way to enhance economic growth. However, the higher production and consumption would also lead to more irrigation water demand and air emissions. The presentation of bioethanol support policies' role in promoting bioethanol along with widespread socio-economic and environmental effects focus are novel. Not only are the results useful for the decision-making towards sustainable bioethanol development, the methods presented in this study should also be a guideline for other socio-economic and environmental impact assessment schemes.