Nanoemulsion-based acai oil was obtained by the phase inversion method using two nonionic surfactants, Ceteareth-20 (Brij (TM) CS20) and polyoxyethylene-hydrogenated castor oil (Croduret (TM) 50), with the concentration of each surfactant varying from 7 to 10 %. The formulation with 10 % Brij CS20 presented the best values for droplet size, zeta potential, and polydispersity index (PDI). Ketoconazole was incorporated into this formulation, with an encapsulation efficiency of 98.31 % and equally good zeta potential, droplet size, and PDI, and spherical shape when observed by transmission electron microscopy. Overall, nanoemulsions of acai oil proved to be a good vehicle for imidazole antifungals such as ketoconazole.