Natural-based composites are gaining popularity among composite makers and end users because of their biocompatibility, low cost, and abundance. The influence of Glycerin as a plasticizer in various percentages ranging from 3% to 12% on Tensile, Flexural, Impact, Inter-laminar Shear Strength (ILSS), and Hardness characteristics of a Kenaf-Jute hybrid polyester composite, which is fabricated using hand layup followed by hot press method, was investigated in the present study. It was observed that a 6% Glycerin concentration in polyester Kenaf-Jute composite outperformed other composites in Tensile, Flexural, and Impact strengths in the range of 2 to 73%. This is evident by analyzing SEM images that better physical bonding between the Kenaf-Jute fibers with modified polyester resin using Glycerin. As the Glycerin content in the composite increases, the Hardness decreases when compared to without glycerin polyester.