To get highly reactive polymeric materials for selective studies of enzyme immobilization, water purification, separation, and enrichment technologies, we attempted to graft 4-vinyl pyridine (4-VP) onto Teflon-PFA by simultaneous gamma -ray initiation. The resulting graft copolymers were quaternized by treatment with some alkylating agents. Optimum conditions for grafting were evaluated through the variation of the total dose of radiation, the amount of water, and the monomer concentration. The effect of the solvent composition (H2O/MeOH) was also studied. In the presence of MeOH, grafting occurred less often and was nonselective as 4-VP was incorporated on both sides in comparison with highly selective grafting in an aqueous medium. The percentages of the grafting, total conversion, and grafting efficiency and the rates of the polymerization, grafting, and homopolymerization were also evaluated. Some other monomers such as methacrylic acid, methyl methacrylate, maleic acid, acrylonitrile, and vinyl imidazole were not incorporated onto the backbone film under the optimum grafting reaction conditions evaluated for the grafting of 4-VP. Although some grafting occurred, the graft yield was too low to be considered of any significance. The grafted films were quaternized with benzyl chloride, and quaternized and unquaternized films were used for the immobilization of lipase. The former showed high activity with lipase and has potential for development as a bioreactor.