Great Smoky Mountains National Park (GSMNP), situated on the mountainous border of North Carolina and Tennessee, is recognized as one of the most highly diverse protected areas in the temperate region. In order to provide baseline data for the scientific management of GSMNP, an All Taxa Biodiversity Inventory (ATBI) was initiated in 1998. Among the goals of the ATBI are to discover the identity and distribution of as many as possible of the species of life that occur in GSMNP. The authors have concentrated on the orders of completely aquatic insects other than odonates. We examined or utilized others' records of more than 53,600 adult and 78,000 immature insects from 545 locations. At present, 469 species are known from GSMNP, including 120 species of Ephemeroptera (mayflies), 111 species of Plecoptera (stoneflies), 7 species of Megaloptera (dobsonflies, fishflies, and alderflies), and 231 species of Trichoptera (caddisflies). Included in this total are 10 species new to science discovered since the ATBI began.