Essential oils are complex mixtures with wide spectrum of biological activities, among them antiherpetic properties has been described in the literature data. However, their use in pharmaceutical formulations is limited due to their lipophilicity, high susceptibility to degradation and volatilization. In this context, encapsulation of essential oils in nanosystems is presented as a flexible and efficient approach to improving their physical stability and therapeutic efficacy. In this context, our group has worked in the development of new herbal medicines for herpes treatment containing EOs. Different nanosystems were developed with Cymbopogon citratus (DC.) Stapf (CcEO) and Rosmarinus officinalis L. (RoEO) essential oils. Polymeric nanoparticles containing CcEO were prepared by emulsification-solvent diffusion method and RoEO nanoemulsion was obtained by titulation process. Both nanosystems had its antiherpetic properties evaluated against HSV-1 and HSV-2 by Vero cells in vitro model and compared with free essential oils. In all cases, the results showed activity improvement when treated with nanoformulations. CcEO polymeric nanoparticles inhibited both HSV strains over 8 times higher than free oil. Altough RoEO showed activity against both HSV types it demonstrated specificity for HSV-2. This viral serotype was inhibited by RoEO nanoemulsion 12 times higher than HSV-1. The results obtained suggest the promising use of different nanosystems containig essential oils that can be future candidates as new herbal medicines for herpes treatment. Our work continues aiming to achieve stable dosage forms with efficacy and safety assurance.