The morphology and anatomy of the seeds of Zanthoxylum rhoifolium Lam. were described and ilustrated, emphazing the seed coat and development.The seeds are obovoid, black, anatropous, bitegmic, exarillate and albuminous. The endosperm is celular with a protein grain storage. The embryo is axial, oblique to seed axis, white, dominant, and the cotyledons have a protein grain storage.