Is sustainable development a policy goal or a legal rule? This paper deals with sustainable development as a legal term, and with the right to aclean environment as a human right. Through analyses of international courts case law it tries to prove that effective execution of the substantive right to a clean environment could improve the application of the sustainable development principle. Following the theory which states that the more legal instruments protecting the environment we apply, the more sustainable development is, this paper surveys the legal instruments of sustainable development that can be used as part of the environmental pillar of development. The paper focuses on judicial protection instruments, considering both private and public interest litigation. The conclusion is that legal instruments for the application of sustainable development are inefficient or inadequate. The environment, often referred to as a“common concern” or as “common heritage” of mankind, has no standing before the courts.