This chapter surveys salient aspects of the practical implementation of sustainable development. It provides some guidance from the ground up, through lessons from South Asia, in particular, public interest litigation in cases concerning economic development, environmental protection and social development, including human rights. The chapter traces the evolution of the concept of sustainable development, culminating in the 2030 Agenda and Sustainable Development Goals (sdgs), and its intrinsic links with international environmental law including the Paris Agreement on Climate Change. Against the backdrop of the larger picture of public international law, the chapter provides practical illustrations of case law from South Asia (especially India, Pakistan, Nepal, Bangladesh and Sri Lanka, with a particular focus on Sri Lanka) wherein judiciaries also engaged in defining sustainable development, giving it practical meaning and tools to achieve it on the ground. The chapter points to examples of a vibrant body of jurisprudence catalyzed by public interest litigation in cases combining human rights, environmental and developmental issues. These could provide good practices in the pursuit of the sdgs, and of sustainable development more generally. The chapter analyzes lawsuits moved by civil society action combined with strategies of innovation by the legal profession, and a certain degree of judicial activism, which could help bring about progressive development in the integration of human rights, environmental and development issues on the ground.