Preparation of high performance nanostructured composites has received increasing interest in the recent years. Carbon nanotubes, in particular, have received wide attention thanks to their low density, as well as excellent mechanical and electrical properties, with Young's modulus (E) approaching 1 TPa and bending strength as high as 63 GPa. For the purpose of mechanical reinforcement, cellulose nanocrystals are emerging as another promising class of material for the preparation of nanostructured composites. The combination of thier natural and renewable origins with exceptional mechanical properties: ó = 10 GPa and E = 150 GPa, make it an attractive nanomaterial for the preparation of low cost, light-weight, and ultra-strong hybrid composites for multitude of applications. In the field of thin film composites, layer-by-layer (LBL) assembly technique has been shown to provide ideal tool for immobilization of the CNTs as well as obtaining hybrids with high loading of the material. With this technique, we have presented recently preparation of composites from both single- and multi walled carbon nanotubes with tensile strength, ó, reaching as high as 250 MPa (in some cases ó reaching 325 MPa) and E as high as 5 GPa. We report here the preparation of cellulose nanocrystals multilayer nanocomposite with poly(diallyldimethylammonium chloride) using layer-by-layer assembly technique. The LBL assembly was characterized with UV-vis absorbance and ellipsometry. Average thickness of a single bilayer was found to be 11 nm. AFM and SEM characterization revealed completely covered and tightly packed layers of cellulose nanocrystals.