The purpose of this study was to develop a sustained release dosage form of chlorhexidine diacetate for topical use. Cast films of ethyl cellulose with or without polyethylene glycol containing 5, 10, and 20 % of the drug were prepared and exhibited sustained release. Chloroform and ethanol were used as casting solvents. Release rate of chlorhexidine from the film was measured by means of a UV spectrophotometer, and kinetics of release were found to conform to Higuchi's diffusional model. This study demonstrates that by embedding chlorhexidine in polymeric films it is possible to obtain sustained release of the drug for several months.