The domatium presents a diversity of forms, and the understanding of the structural aspect of the domatia is very important because it can provide diagnostic characters for families and genera, and favors the establishment of mutualistic relations. The objectives of the present study were to characterize the developmental stages of the domatia of Schinus terebinthifolius Raddi. (Anacardiaceae) located at the base of the leaflet, and based on these data to determine if the structural aspects provide good shelter for mites and ants. Domatia were observed under a stereomicroscope and then processed following standard techniques for light and scanning electron microscopy. The domatia of S. terebinthifolius develop early during the development of the leaves and go through four stages of development. The domatia have a spiraling architecture with internal chambers that contain trichomes and stomata, suggesting good conditions of shelters for arthropods. Deposits of phenolic compounds and calcium crystals were identified in the domatia, suggesting an investment in alternative forms of protection from herbivory. Structural analysis showed the developmental stages of domatia and how the architecture of these structures can provide efficient shelter for arthropods, thereby contributing to the protection of these plants from herbivory and facilitating ecological studies.