Rising pollution levels, desertification, urbanization, water shortages, climate change and biodiversity losses are some of the well-documented environmental threats facing humanity. Countries at the regional and international level have been attempting to negotiate and agree framework laws and policies to govern activities that protect the environment and advance development. There has been a growing realization at both the national and international levels that the effective implementation of environmental regulations requires balance between developmental concerns and environment protection. Contrary to the passive jurisprudential acknowledgement of this balance in the law lexicon, there is evidence that, in some states, the judicial process has played an activist role in evolving substantive and procedural rules to balance the protection of environment and development. By way of a key example, the Indian judiciary has expanded the ambit of constitutional provisions to incorporate environmental concerns and incorporated international environmental principles as part of domestic international environmental law implementation. Judges have also created unique environmental principles such as the principle of absolute liability, which is gradually finding its way into the international legal framework. Invocation of innovative procedural devices such as public interest litigation (PIL) has also constituted a prominent feature of Indian environmental judicial activism. The doctrine of sustainable development has been adopted as a core principle to balance development and environmental concerns. This chapter explores the central, pivotal role that the judiciary has played in balancing the environment and development.