Natural rubber is a renewable resource material and imparts excellent mechanical and dynamical mechanical properties to the rubber products. carbon black and silica are the most essential reinforcing fillers in the rubber industries. carbon black enhances the mechanical properties, while silica has its own advantage over carbon black filler as it reduces the rolling resistance in tyres and enhances the wet grip characteristics. carbon blacks at higher loadings require process aids for easier processing and improved filler dispersion. aromatic oils have been used so far in the rubber industry as plasticizer and process aids. presence of polycyclic aromatic hydrocarbons (pahs) in these oils have raised concerned and has been banned. rubber industries are looking for alternate sources of process aids from renewable resources. moreover, the dispersion of polar inorganic silica fillers in the nonpolar hydrocarbon rubbers like natural rubber is a serious issue to be resolved. in recent years, it has been discovered that, cardanol (m-pentadecenyl phenol), an agricultural renewable resource, a by-product of the cashew industry is cheap and abundantly available. it can act not only as a green plasticizer but also as a multifunctional additive in the rubber. grafting of cardanol on to natural rubber in the latex stage was carried out successfully at room temperature using cumene hydroperoxide and tetraethylene pentamine. the grafted natural rubber was characterized by ftir, nmr and gel permeation chromatography. grafting of cardanol on to natural rubber has resulted 45.6 % increment in the molecular weight without affecting the molecular weight distribution. taguchi method was used to optimize the grafting conditions to achieve maximum yield in terms of percent grafting and grafting efficiency. the optimal parameter combination was found to be initiator concentration 2 phr, cardanol concentration of 10 phr, reaction temperature of 35 °c and reaction time of 10 hours. the percent grafting was found to be 8.25% and grafting efficiency was 82.5 % for the optimum parameter combination. differential scanning calorimetry and dynamic mechanical analysis exhibit lowering of the glass transition temperature of the cgnr as compared to the raw natural rubber. this confirms the plasticization effect of the cardanol when grafted onto the natural rubber. the dispersion of carbon black and silica filler is evaluated in cardanol grafted natural rubber (cgnr) and compare with that of oil plasticized natural rubber. the physico-mechanical properties of the cgnr vulcanizates are better than that of the aromatic oil plasticized nr vulcanizates. the crosslink density and bound rubber content are higher and payne effect is lower for the cgnr vulcanizates as compared to oil plasticized nr vulcanizates. the transmission electron microscopy images show uniform dispersion of the carbon black and silica fillers in the cgnr matrix. in conclusion, cardanol-g-natural rubber is a potential substitute for aromatic oil plasticized natural rubber for carbon black filled compounds and imparts multifunctional activity to natural rubber after grafting. moreover, cardanol also acts as a dispersion enhancer in the rubber matrix imparting better rubber-filler interaction and thus, leading to higher reinforcement in case of silica filled compounds. in future, it may emerge as a new commercial grade of natural rubber, with technical and economic advantages.