Biocidal elastomeric materials have been produced by a three-step chemical process on commercial elastomers which are composed of a styrene/ethylene-butylene/styrene triblock copolymer. The commercial elastomeric material employed was Kraton®G, produced by the Shell Chemical Company in Houston, Texas. The three-step process involved a Friedel-Crafts acylation of the styrene blocks of the elastomer, followed by a hydantoin ring formation reaction, and subsequent halogenation with chlorine or bromine. Both raw and processed elastomeric materials were studied. The biocidal efficacies of the materials were demonstrated using several species of bacteria. A few applications for the technology may include prevention of disease by biocidal surgical gloves, condoms, protective clothing, food packaging, and the prevention of biofouling in elastomeric tubing.