ABSTRACT Sixteen commercial insect repellents (6 botanical and 10 synthetic organic products) in spray formulations were evaluated in the laboratory for adult knockdown (KD) and mortality of laboratory-reared female Aedes aegypti, Aedes albopictus, and Anopheles quadrimaculatus. All tested products produced significant posttreatment KD and 24 h mortality of all 3 mosquito species. In our study, the synthetic organic repellents induced faster KD and KD of higher magnitude in adult mosquitoes than the botanical product repellents except geraniol-based MosquitoSafe. All tested formulations except 2 botanical repellent products caused 100% 24 h mortality of Ae. aegypti and all but 1 caused 100% 24 h mortality of Ae. albolpictus and An. quadrimaculatus.