Fibre-plastic composites were fabricated using rubberwood (Hevea brasiliensis) fibres blended with polypropylene at different fibre contents (20, 40, 60 and 80% by weight) and fibre size fractions (<0.5, 0.5-1.0, 1.0-2.0 and >2.0 mm). The tensile strength of the composites decreased as the fibre content increased. Flexural strength tended to increase with an increase in fibre content, attaining a peak value at 40 to 60% fibre content. Impact strength for these composites had a maximum value at 60% fibre content. Hardness declined as more fibres were added into the composites. In the usage of different fibre size fractions, tensile strength decreased as fibres were getting longer. The opposite was shown for flexural strength and impact strength. Increased fibre size fractions reduced the ability to resist indentation in hardness test.