This article presents the overall morphological structure of the Brazil nut tree (Bertholletia excelsa) fruit pericarp, from macro to nano scale. The acquired knowledge would be used for the development of new applications, like using the materials as fillers for biocomposites, or as a hierarchical architecture model for biomimetics. This research was performed using stereo and light microscopy and conventional and force field emission scanning electron microscopy. The pericarp presents three layers: the exocarp, a dark gray, brittle and fragile outer layer; the mesocarp, a beige, dry, rigid, impermeable and fibrous intermediate layer; and the endocarp, an inner layer with similar characteristic as the exocarp, but formed next to the seeds. Morphologically, the exocarp and the endocarp presented minor regions of sclereids, fibers and vascular cell bundles, inside major regions of parenchyma cells. The mesocarp presents a structure of fiber cells regions alternating with sclereids and vascular cells regions, arranged in a composite like arrangement, with the fibers cells bundles acting as randomly oriented disperse phases in a sclereid cells matrix. This arrangement was associated with the mesocarp relative superior proprieties, indicating a great material for using as fillers for biocomposites or in biomimetics applications.