Ultrathin films containing a high fraction of cellulose nanowhiskers embedded in an acrylic-based polymer matrix were successfully prepared by a shear-convective assembly method. Their morphological, chemical and physical properties were examined by AFM Peak Force Tapping, Ellipsometry, contact angle and X-ray photoelectronic spectroscopy (XPS). Smooth, stable, robust and hydrophobic ultrathin films were obtained. The processing conditions influence, to different extents, the organization and morphology of the resulting ultrathin films. Under the given experimental conditions, films with highly packed and oriented cellulose nanowhiskers were obtained. A post-treatment based on UV-curing allows a further enhancement of the stability of the films without impacting any other property.