This paper explores a relatively neglected aspect of understanding the post-environmental judgment scenario: the impact of environmental judgment at the grassroots level and why there has been variation in the implementation of environmental judgments. It examines two Supreme Court environmental judgments on industrial pollution in two different states of India-the Dahanu Power Plant Case in Thane District of Maharashtra and the leather industrial pollution case in Vellore District of Tamil Nadu-and raises one central question-what factors determine the effective implementation of Supreme Court’s environmental judgments. The premise of this paper is that, despite the existence of a well-established regulatory framework to enforce environmental laws and policies in India, there has been a variation in the implementation of environmental judgments. From the judicial activism perspective, emphasis is placed on how the nature and level of judicial intervention in the post-judgment scenario, ensures the effective implementation of its own directions. It is argued that judicial intervention in the implementation of its decisions has become crucial to enforce its directions, and that this intervention is undertaken not to take away the power and functions of implementing agency, but rather to translate its directions into action at the grassroots level. In turn, the successful enforcement of environmental judgments depends on the nature of judicial activism, or the way in which the judges bring changes in the implementation process. As a consequence, it is not the level of judicial activism in itself which is decisive, but the process of activism that contributes towards the effective implementation of its decisions. In establishing this argument, however, the paper also argues that the process of judicial activism in the implementation of its direction is triggered by the active and consistent involvement of civil-society groups at the grassroots level. It is also found that the consistent presence of civil society in monitoring the implementation of judicial decisions is largely dependent on the resource capacity of the civil-society groups. The paper argues that the striking differentiations at the implementation level in these two above-mentioned cases can be attributed to the nature and level of judicial activism triggered by the active and consistent presence of civil society groups.