Polyurethane samples were prepared from rubber seed oil monoglyceride (made by reacting rubber oil with glycerol) and diiosocyanates (hexanethylene and toluene diiosocyanates). Polyurethane composites were made by compression moulding using biofibres; sisal, jute and banana; in random and unidirectional orientations at different fibre lengths and loadings, as reinforcing elements. The composites were characterized in terms of tensile and flexural strengths and moduli, thermal stability and morphology of fractured surface. The values of the measured mechanical properties (tensile and flexural) of the composites were about 3-fold higher than the properties of the unreinforced polyurethane samples, suggesting good reinforcement by the biofibres. The absence of fibre-pull-out on the scanning electron micrographs of the fractured surface provides evidence in support of good adhesion between the biofibres and the polyurethane matrix. The thermal stability of the composites was lower than for the fibre but higher than for the unreinforced polyurethane.