Did the recent UN Conference on Environment and Development (UNCED) conclude with only pious aspirations or solid achievements? Among the documents adopted at UNCED was Agenda 21, an ambitious plan of action to tackle both global and national environmental problems, a Statement of Principles on Forests, and the Rio de Janeiro Declaration on Environment and Development. This article considers what influence, if any, the Rio Declaration might exert in relation to the further development of international environmental law.