What role can public participation play in environmental management? Among major tools for environmental management, Environmental Impact Assessment (EIA) has been widely practised in many countries. Its effectiveness, however, varies depending on the extent to which transparency and public participation are incorporated in its process. In this article, we analyse the role of public participation in environmental management by examining the operation of EIAs in two polities, Mainland China and Taiwan. In both cases, a lack of transparency and public participation had severely limited the effectiveness of EIA during the initial years when it was first introduced. Both polities have attempted to address the respective limitations of their EIA systems, and both have made some progress while encountering problems inherent in their underlying political institutions. The two cases illustrate the dynamic connections between political institutions and environmental management in developing countries.