The natural fibre-reinforced polymeric composites attract the manufacturing industries due to their recyclability, cost-effectiveness and eco-friendly nature. The natural hybrid reinforced polymeric (HNRP) composite overcomes the limitations in mechanical properties of the mono-natural fibre-reinforced composites. In this research work, the effect of barium sulphate (BaSO 4) on the mechanical characterization of HNRP (aloevera/flax/barium sulphate) composites was examined as per ASTM standard. BaSO 4 is preferred as a filler based on the absence of self-motion, high density and high melting point (1580∘C). The thermal stability of the HNRP composite was determined by thermogravimetric analysis (Model: TG/DTA 6200). The water absorption and dynamic mechanical properties of the HNRP composites were estimated. The fractography images were analysed to recognize the fractured surface morphology using a scanning electron microscope. The HNRP5 composite has the maximum tensile strength of 34.72 MPa, predominantly based on the interlocking of the flax fibre and plasticity of the composite improved by the influence of BaSO 4. The impact strength decreased noticeably with the addition of barium sulphate in the composite. The weight reduction of around 7–9% was observed in the temperature range of 100–200∘C. The mono-composites (HNRP1&2) absorbed, respectively, 4.8 and 3.5% of moisture; with the addition of BaSO 4, the same combination absorbed 4.2 and 3.2% of water content, which was due to the low water absorption capability of BaSO 4. The storage modulus of the HNRP5 composite has maximum magnitude in the glassy region and minimum in the rubber region. © 2020, Indian Academy of Sciences.