This study evaluated the acaricide efficacy of Piper macedoi essential oil on larvae of ticks of the species Rhipicephalus sanguineus. The essential oil was extracted by hydrodistillation in a Clevenger-type apparatus. The test consisted of six treatments: from the group I to IV, samples corresponded to different concentrations of essential oil (500 μg.mL-1; 250 μg.mL-1; 100 μg.mL-1 and 50 μg.mL-1) diluted in Tween 80 at 2%. Groups V and VI corresponded to the negative controls (with distilled water and Tween 80 to 2%) and the positive control (with acaricide Amitraz at 12.5%), respectively. The essential oil was rich in apiole (39.81%) and dillapiole (26.47%). The essential oil of P. macedoi presented an activity against the larvae of R. sanguineus, with a better efficiency observed for concentrating 500 μg.mL-1, mortality of 80.67%, indicating a dose-dependent response.