The present work of this book aims to prepare fast dissolving films of Losartan Potassium with purpose of developing rapid onset of action, which is very convenient for administration without using water. The films were prepared by solvent casting method. The plasticizer concentration was selected on the basis of flexibility, tensile strength and stickiness of the film. In the present study polyethylene glycol was used as plasticizes. Fast dissolving films were evaluated for drug content and the drug loading capacity. The dissolution profile and folding endurance were found to be satisfactory. The disintegration time of formulation F3 film was lowest (30 sec), so they release drug faster than other formulations.A drug-excipient interaction was performed by DSC and FTIR; results were shown that there was no interaction between drug and excipients used. In vitro release mechanism was evaluated by subjecting the dissolution data to various kinetic models and the drug release was found to best fit theKorsemeyer-peppas model. Hence it is concluded that Losartan Potassium fast dissolving films are successfully developed and evaluated.