This work deals with the influence of multiple injection moulding cycles on the properties of wood flour reinforced polypropylene (PP) composites. The initial wood particle size in the range of 70-150 μm and 200-500 μm was first studied. Then, the influence of the addition of a coupling agent such as polypropylene grafted with maleic anhydride (PPgma) at a given rate was investigated. Biocomposite compounds (20wt% of wood flour) are produced by twin-screw extrusion. Then, multiple injection/grinding cycles were performed (up to 7 passes) to obtain normalized samples. Mechanical (tensile, impact) and thermal (cristallinity rate) properties of the biocomposites are evaluated. The change of viscosity is assessed through rheological measurements.