Graft copolymerization of methyl methacrylate (MMA) onto jute substrate was carried out using gamma radiation (Co-60) both by the preirradiation and "simultaneous irradiation and grafting" methods in an aqueous emulsion system. The variation of graft weight with radiation dose, intensity of radiation, and irradiation environment was investigated. In the case of the preirradiation method, irradiation in air produced up to 30% graft weight compared to only 20% obtained when the irradiation was conducted in nitrogen environment. In this method the graft copolymerization reaction was initiated by reactive species having different life times, some of which were very long. In simultaneous irradiation and grafting method, the graft weight passes through a maximum value (similar to15%) with radiation dose and graft weight limited due to excessive homopolymerization. A comparative study on the mechanical properties of samples grafted by both preirradiation and simultaneous irradiation and grafting methods was, carried out. The results showed that the method of grafting has significant influence on the mechanical properties of grafted jute.