The study was designed to evaluate the ethanolic extract acaricide action from Pouteria gardneriana Radlk specie adsorbed in chitosan nanoparticles for controlled release against Riphicephalus (Boophilus) microplus. Leaves of P. gardneriana Radlk were collected, air-dried, ground and extracted with ethanol. Chitosan nanospheres were obtained by the phase inversion method. Conductometric titration, UV-Vis and FTIR analysis were conducted with the materials to evaluate the chitosan anchoring ability. In vitro test was performed using engorged females for each treatment, which consisted of the control, raw extract and three treatments diluted, with increasing concentrations of 0.2, 0.4 and 1%. The most effectiveness extract was for 0.4% concentration by observing reduction in the eggs mass compared to control group. The nanomaterial proved to be able to anchor and release the insecticide gradually in pH between 5 and 6 regions, which makes it feasible for use in cattle, prolonging the exposure time between the tick and acaricide.Key words: Extracts, nanoparticle, controlled release, tick.