The importance of environmental certification in the realm of corporate sustainability has been widely discussed, but existing management literature has mostly focused on the gap between adopting and implementing the scheme with the concept of policy-practice decoupling. I suggest that prior studies have neglected the actual goals and outcomes of environmental certification, and that the notion of means-ends decoupling clearly explains the gap between its implementation and results. That is, environmental certification schemes are duly implemented and evaluated, yet such activities are not linked to enhancing environmental performance and moving towards accomplishing sustainable development. Using empirical data from the Korean Green Certification program, a government-initiated scheme for formally recognizing sustainable technologies, the study finds that the duration of certification is a key source of variation in the limited outcomes of implementing environmental certification. The findings also show that the main effect of certification duration is negatively moderated by the degree of implementation efforts themselves. The implications for organization studies and environmental policies are discussed.