The efficacy of a new smoke-generating formulation (fumigant), containing the active ingredient permethrin (69 g/kg) and deltamethrin (3.9 g/kg) per cartridge, was evaluated against adult female Anopheles albimanus, Aedes aegypti, and Culex quinquefasciatus in a large vehicle storage building (22 × 13 × 4.5 m³), Florida, USA, and against Cx. pipiens complex and Ae. albopictus in a furnished apartment (12 × 7 × 3.5 m³) in Israel. In the storage building, the use of 2 fumigant cartridges resulted in 100% mortality for all 3 species in 15 min. Using 1 cartridge resulted in 100% mortality in An. albimanus, 98% in Ae. aegypti, and 97% in Cx. quinquefasciatus in 15 min; and 100% mortality for both Ae. aegypti and Cx. quinquefasciatus at 30 min. In the apartment in Israel, both Ae. albopictus and Cx. pipiens showed 100% mortality when exposed to the fumigant cartridge for 15 min. Based on these preliminary data, the test formulation (fumigant) could be a valuable tool for controlling mosquitoes.