Jute and flax fibers were improved under UV radiation using methyl methacrylate (MMA) mixed with methanol (MeOH). There was a 30% enhancement of tenacity for these fibers against 3-8% grafting of MMA with the fibers. Incorporation of 1% of one of the additives 2-ethyl hexyl acrylate (EHA), urea (U), or N-vinylpyrrolidone to MMA + MeOH solution increased the grafting very slightly and enhanced the tenacity of jute by 110% and flax by 50%. Enhancement of elongation of the treated fibers was up to 30%.