Green manufacturing is globally recognized. However, there is a paucity of empirical data in the literature on how green manufacturing can be adopted by medium-sized firms in developing countries, including Southwest Asian countries such as the Republic of Yemen with volatile and uncertain business environments. This study examines the impact of operational excellence and innovation on the green manufacturing of medium industrial enterprises in the Republic of Yemen, based on the literature on operational excellence and innovation. Using Smart PLS 3.0 software, partial least squares structural equations modeling was used for (243) valid questionnaires based on a sample of (10) medium industrial companies in the Republic of Yemen. The results show that a variety of factors, including the adoption of a national policy that supports the idea of green manufacturing at the national level, can encourage green manufacturing in medium industrial firms. However, the application of operational excellence and innovation in a participative management approach and collaborative culture at the company level has a beneficial effect on and encourages the green manufacturing of such businesses. This study adds to the body of knowledge regarding green manufacturing and how it applies to the manufacturing of medium-sized firms in unstable emerging countries political and economic surroundings like the Republic of Yemen. Moreover, the research findings highlight the importance of operational excellence and innovation for medium-sized industrial enterprises operating in a highly competitive and volatile market.