Nanotechnology applied to pulp and paper sector enables production of nanostructured papers with excellent strength properties. The addition of lignocellulose nanofibrils (LCNF) to traditional kraft pulps is an attractive alternative for production of improved packaging papers. In relation to cellulose nanofibrils (CNF), LCNF application in unbleached papers has the advantage of eliminating the costs of bleaching chemicals and potential advantages in drainage. One aim of this study was producing and characterizing LCNF from eucalypt (E) and pine (P) unbleached pulps and comparing the results with the traditional CNF. Another aim of the work was evaluating LCNF as an additive for production of kraftliner and sackraft nanostructured packaging papers. LCNF proved to be a viable additive for the production of high-strength nanostructured papers while relying on low energy consumption during the refining process. LCNF addition had positive effects on the mechanical properties of the nanostructured papers produced, resulting in significant increases in strength properties.