This study evaluated the insecticidal activity of Gallesia integrifolia essential oil from fruits, leaves, and flowers against Aedes aegypti larvae and pupae. The essential oil was obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry. Sulfur compounds represented 95 to 99% of the essential oil from fruits, leaves, and flowers. Essential oil major compounds were 2,8-dithianonane (52.6%) in fruits, 3,5-dithiahexanol-5,5-dioxide (38.9%) in leaves, and methionine ethyl ester (45.3%) in flowers. The essential oils showed high activity against larvae, and low for pupae with LC99.9 of 5.87 and 1476.67μg/mL from fruits; 0.0096 and 348.33 μg/mL from leaves and 0.021and 342.84 μg/mL from flowers, respectively. The main compound with insecticide activity is probably n-ethyl-1,3-dithioisoindole, from isoindole organothiophosphate class, found in greater amount in flower and leaf essential oil. The great insecticide activity of G. integrifolia essential oil suggests that this product is a natural insecticide.Este estudio evaluó la actividad insecticida del aceite esencial de frutas, hojas y flores de Gallesia integrifolia contra larvas y pupas de Aedes aegypti. El aceite esencial se obtuvo por hidrodestilación (3 h) y se caracterizó por cromatografía de gases y espectrometría de masas. Los compuestos de azufre representan 95 a 99% del aceite esencial. Los principales compuestos fueron 2,8-dithianonane (52.6% en frutos), 3,5-dithiahexanol-5,5-dioxide (38.9% en hojas) y methionine ethyl ester (45.3% en flores). El aceite esencial mostró alta actividad contra las larvas y baja para las pupas de A. aegypti con LC99.9= 5.87 μg/mLy 1476.67μg/mL en frutos, 0.0096 y 348.33 μg/mL en hojas y 0.021 y 342.84 μg/mL en flores. El compuesto principal con actividad insecticida es probablemente el n-ethyl-1,3-dithioisoindole, de la clase de organotiofosfato isoindol, que se encuentra en mayor cantidad en flores y hojas. Los resultados sugieren que esta especie puede convertirse en un bioinsecticida.