SUMMARY Introduction: The validation concept refers to the statistical evaluation of the results obtained in the application of analytic technics, by appropriately documented and demonstrative tests that a method is sufficiently reliable to produce the result foreseen under defined conditions, like they are: analytic system, concentration interval, infrastructure and human talent. Objective: To describe the validation process of the analytic method for the valsartan quantification in human plasma by HPLC- UV and its application in pharmacokinetic, bioavailability and bioequivalence studies of products that contain the active principle valsartan. Methodology: A method for detection and quantification of valsartan in human plasma has been developed using an isocratic elution on reversed phase liquid chromatography with ultraviolet detection at a single wavelength (265 nm) and the addition standard method. Losartan was used as an internal standard. This method involves a solid-phase drug extraction (valsartan and losartan) from plasma using C 8 cartridges. Separation was achieved on a C 18 reversed phase column and the mobile phase consisted