The Lusk Creek Watershed, located in Pope County, IL, long has been recognized as a high quality area and as biologically significant. Yet, surveys of the macroinvertebrate fauna have been limited. Thus, a survey of the benthic insect community in the upper portion of Lusk Creek was conducted from May 2003 to April 2005. Eleven sites were selected and characterized by physical properties and water chemistry. Insect distribution patterns, abundance, and diversity (richness, evenness) were examined. A total of 20,888 specimens, mostly immatures, were examined during the study and represented eight orders. The Diptera, by far, was the most common order, with 18,590 specimens, almost all of which were members of the Chironomidae and Simuliidae. The EPT (Ephemeroptera, Plecoptera, Trichoptera) combined were common with 1,550 specimens but paled in comparison to the Diptera. The Coleoptera was represented by 647 specimens, almost all of which were members of Stenelmis (n = 612). The Shannon diversity index (H') showed that the H' values for individual sites were similar to those reported for other relatively undisturbed streams. Analyses of richness suggested that as many as 37 taxa were unobserved, indicating the survey was incomplete.