In 1974 the U.S. Fish and Wildlife Service directed its Office of Biological Services to design and conduct a new national inventory of wetlands. For a number of reasons, it was decided that an attempt be made to develop a new wetlands classification system that would fit the needs of a broad spectrum of users and provide flexibility required for the incorporation of new knowledge concerning wetlands. A meeting was held in January 1975, to explore the possibilities of developing a new and better classification system. A relatively few wetlands experts from various sections of the United States attended that meeting. The first draft of a new system evolved from that meeting. It was then decided that the draft version should be critically reviewed by a much broader representation of wetland workers. The workshop reported on here represents the attempt to obtain that input, and at the same time review the current status of wetlands work being carried on by certain governmental and private agencies. The "Interim Classification of Wetlands and Aquatic Habitats of the United States: appended to these proceedings incorporates many suggestions emanating from the workshop. As the title indicates, this is an interim classification; it must be field tested and refined before a final version is prepared.