The National Environmental Policy Act (NEPA) was signed into law by Richard M. Nixon on January 1, 1970; this year marks its 35th birthday. NEPA was the first of the major environmental statutes passed during the Nixon and Ford administrations. Its requirement that the environmental consequences of actions be evaluated before implementation has been copied by a number of states, some municipalities and tribal governments, and over 100 other jurisdictions around the world. We believe this is an appropriate time to look at some of the issues surrounding NEPA and make suggestions regarding future directions.The authors acknowledge the contribution of ideas by Helen Ingram, University of California, Irvine; Jo Ann Beckwith, Michigan State University; and Jon Allan, CMS Energy Corp. The Editorial Staff is grateful to Michael R. Thomas, Environmental Practice Advisory Board, for his role in obtaining this manuscript. A portion of this article first appeared as a letter to the editor in Science 307:674 (February 4, 2005).