In this laboratory study, we applied 3 formulations of permethrin (Peregin® 500 EC, Dragnet®500 EC, and Dragnet® 100 ME) and 2 of bifenthrin (Biflexo® l0 ME and Talstar® 80 SC) to swatches of Australianmilitary shirt fabric. The knockdown and mortality of Anopheles farauti and Aedes aegypti after exposure totreated fabrics were compared. The mortality of An. .farauti exposed to permethrin-treated swatches for 3 minin World Health Organization test kits was 94.2-100% after initial treatment and fell to <28% after 2 cold waterwashes, and knockdown was <20% after 3 washes. The mortality of An. farauti exposed to bifenthrin-treatedswatches was initially 100% and remained >55% after 3 washes, whereas knockdown was <25% after 2 washes.Morlality of Ae. aegypti exposed by tarsal contact to permethrin- and bifenthrin-treated fabrics was 84.8-100%prior to washing and fell to <21% and <40%, respectively, after 1 cold water wash. The ability of Ae. aegyptito obtain a blood meal through treated fabrics was variable, and a small percentage (0-6.l%) of mosquitoesobtained a blood meal through fabrics after initial treatment. The effect of cold water washing on the persistenceof both chemicals in fabric by chemical assays showed that between 58% and 66% of both chemicals was lostfrom the test fabric after a single wash.