More than 230 species of benthic macroinvertebrates are recorded from Kentucky Lake, a major reservoir on the Tennessee River system, and compiled in an annotated list. Chironomidae (Diptera) and Unionidae (mussels) comprise more than 60% of the total taxa. Most species are restricted to shallow or marginal areas of the lake with only about 12 being common everywhere. The common species were similar to those found in both large and small reservoirs in the eastern United States. High disturbance regimes and sedimentation patterns are thought to control the similarities, limiting the communities to a small suite of adaptable species. This may reduce the usefulness of reservoirs in understanding climate change. A small number of invasive benthic species are well-established but appear to have had little affect on the rest of the benthic community. Invasive zooplankton and fish seem to have had little influence on the benthos, but the recent invasion of silver carp, Hypophthalmichthys molitrix (Valenciennes), may be a tipping point.