Aedes aegypti is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways of controlling this mosquito, the larvicidal activities of essential oils from Croton species widely found in northeastern Brazil were analyzed. The essential oils were extracted by steam distillation, and their chemical composition was determined by gas liquid-chromatography coupled with mass spectroscopy. The main components were methyleugenol and α-copaene for C. nepetaefolius (LC₅₀ of 84 ppm); α-pinene and β-pinene for C. argyrophyloides (LC₅₀ of 102 ppm); and α-pinene, β-phelandrene, and transcaryophyllene for C. sonderianus (LC₅₀ of 104 ppm). Croton zenhtneri exhibited higher larvicidal activity with LC₅₀of 28 ppm, and the main active constituent was identified as anethole, a phenylpropanoid compound.