INTRODUCTION In this work, our aim is to study the synergistic effect of wool natural fibre hybridization to intumescent kenaf/polypropylene composite and thereby analyse the thermal property improvement of the hybrid composite. MATERIALS AND METHODS High crystalline block copolymer polypropylene (PP, supplied by Clarient, New Zealand) was used as the matrix material for sample preparation. Kenaf bast natural fibre yarns (supplied by Bruce Smith Limited, New Zealand) were cut and grinded into average length of 2.5 mm, and then mixed with maleic anhydride grafted polypropylene (MAPP; supplied by Clarient, New Zealand Ltd.). Intumesent APP (Supplied by Chemcolour Industries New Zealand Limited) was used as the initial flame retardant by combining wool (supplied by Bloch & Behrens Wool New Zealand Limited) as the synergistic hybridization flame retardant additive. Phas-o-mec high intensity turbo mixer was used to dry mix the compound before thermal blending through intermeshing co-rotating scientific twin screw extruder. Boy 50 A injection moulder was used to manufacture the test samples. RESULTS AND DISCUSSION Flammability Characteristics and Thermal Behaviour Sustainable combustion of neat PP and natural fibre composites have been analysed using Underwriters Laboratory Vertical Burning Test (UL 94V). Adding wool into the system, the flame retardant performance of the intumescent kenaf/PP composite has improved significantly. The cone calorimeter test has shown lower pk-HRR (Table 1 and Figure 1a), thus establishing higher flame retardant performance in the synergistically hybridized compound.. Thermogravimetric analysis (TGA - Figure 2b), shows the thermal degradation behavior of the materials and their remaining char residues at the end of combustion. The higher amount of char residue remaining in the compound containing wool may have contributed to the synergism with natural fibre hybridization in in intumescent kenaf/PP composites.