Environmental protection is an issue that all developing countries must cope with when inviting foreign direct investment (FDI). However, the high correlation between FDI and pollution does not necessarily indicate that foreign firms are to blame. In this study, we apply firm-level panel data from Vietnam and unique information on waste discharge to demonstrate that foreign firms are actually more proactive in acquiring ISO14001 certification. ISO14001 is a voluntary environmental standard, the adoption of which improves a firm's performance in terms of waste control, and increases its welfare and productivity level. This study provides robust evidence that firms' efforts toward corporate social responsibility eventually benefit them as well.