The project calls upon the development of composites and nanocomposites of acrylic matrix filled with cellulose pulp fibers (CF) or nanofibers (NFC) for the preparation of panels with high content of cellulose (75, 50 and 25 % wt). The problem of low compatibility of the hydrophilic cellulose with hydrophobic matrices normally leads to non homogenous materials. In order to overcome the problem, a new process was proposed. Here, the CF or NFC emulsion were mixed with an aqueous acrylic solution and the composite was obtained dewatering assisted with vacuum. The process led to the formation of a homogeneous composite that was molded by hot pressing. The composites were characterized by SEM, FTIR, TGA, DMA, water absorption and mechanical tests. The typical chemical feature of the composites was accessed by FTIR and their fibers/matrix contents by TGA. SEM showed the good dispersion and interaction of the CF and NFC with the matrix, with no pull out for both composite types. DMA and tensile tests confirmed the dispersion and good adhesion of CF and NFC with the matrix, by an extraordinary reinforcing effect, specially for the composites based on NFC.