Editors' Summary: The doctrine surrounding the rights of individuals to pursue legal remedies in the courts has a long and complex history, and has resulted in a patchwork of rules that are not always easy to follow. Standing to sue limitations have their origins in Article III of the United States Constitution, which limits federal jurisdiction to "cases and controversies." In the early 1970s, the Supreme Court paved the way for environmental groups to participate directly in the evaluation of environmental law by liberalizing the rules pertaining to standing. Congressional expression of standing requirements is found in the Administrative Procedure Act, which provides for access to the courts to persons "adversely affected or aggrieved" by the actions of federal agencies, and the citizen suit provisions found in many of the environmental statutes enacted in the 1970s and 1980s. Together, these judicial and congressional expressions establish certain conditions for standing that, until recently, many environmental litigants thought were fairly easy to satisfy. Several recent judicial decisions may cause them to rethink this conclusion, however. This Comment reviews the established rules of standing in light of these decisions. The author discusses the cases, most of which arise in the D.C. Circuit, and examines their practical implications for environmental organizations.