This study aimed to determine the chemical constituents and larvicidal activity of the essential oil of Plectranthus amboinicus (Lour.) Spreng against larvae of the Aedes aegypti mosquito. The essential oil (EO) was extracted by hydrodistillation at 100 ° C for 3 hours. The chemical composition was obtained by Gas Chromatography coupled to Mass Spectrometry (GC / MS). To assess larvicidal activity, Aedes aegypti larvae were subjected to EO solutions in concentrations of 10-100 mg L-1, where larval mortality was assessed and the LC50 was determined using the Probit method. The main chemical constituent found in the EO was carvacrol, which is considered to be very promising for pharmaceutical synthesis. The EO showed larvicidal activity with an LC50 of 28.52 mg L-1. According to the results found, it was possible to evaluate that the analyzed EO is composed of substances that have an efficient larvicidal effect against Aedes aegypti, thus encouraging its potential for application.