Great Smoky Mountains National Park (GSMNP) contains one of the most diverse assemblages of vegetation communities in North America. Over 70 unique community associations comprised of over 1300 native plant species have been identified in the Park. This wide array of communities provides habitat for unknown multitudes of other taxa whose abundance, distribution, and ecological importance remain largely unknown. The All Taxa Biodiversity Inventory (ATBI) underway in the Park is the first comprehensive attempt to better understand the vast array of species present in the Park. This paper discusses the composition, structure, distribution, and extent of vegetation communities in GSMNP. Detailed assessments of the vegetation, site, and soil characteristics of the 19 ATBI plots are also included.