During 2004 and 2005 insects were collected on or adjacent to Plummers Island, Montgomery County, Maryland using an ultraviolet light trap (2004 (2005) and two Malaise traps (2005). Forty-seven species of Trichoptera were identified from this material, representing 13 families and 25 genera. Most of the species are common and widely distributed over eastern North America, and none is considered of special concern or sensitive.