Six families, 18 genera, and 34 species of Trichoptera are reported from Carroll County in western Iowa of which 18 are new state records. Hydropyschidae, Hydroptilidae, and Leptoceridae made up over 80% of the caddisfly fauna. The caddisfly assemblage corresponded to streams that were highly altered by agricultural activity with heavy sedimentation and reduced canopy cover. Supplemental collections from central and eastern Iowa were also made. Assemblages in Carroll County were markedly different than those in the Paleozoic Plateau/Coulee Section in northeastern Iowa. We located an additional 14 species records in the literature and have an additional 13 new state records, primarily from central and eastern Iowa collections, for a total of 63 caddisfly species now reported for the state.