<p>Energy inefficiency and environmental pollution are the major obstacles to green development in developing countries. This study investigates the relationship between exporting, energy efficiency and pollution emissions at firm level. To guide empirical work, we introduce energy and pollution into the Melitz ’s (Econometrica 71(6):1695–1725, 2003) framework and construct a theoretical model. Then, we employ firm-level data from China to empirically examine this relationship. Our results indicate that compared with non-exporting firms in the same industry, exporting firms have higher energy efficiency and thereby fewer pollution emissions. Energy efficiency is an important channel between exporting and pollution emissions. In China, exporting firms are cleaner mainly because of higher energy efficiency rather than the channels of productivity and abatement technology, which is different from developed countries. This advantage of environmental performance is driven by both self-selection and learning-by-exporting. Especially, exporting further improves energy efficiency and reduces emission intensity. Overall, this study provides the first theoretical framework and evidence for the relationship between exporting, energy efficiency and pollution emissions, and also provides implications on trade and environmental management for developing countries.</p>