A Reversed-Phase High Performance Liquid Chromatographic (RP-HPLC) method for simultaneous and separate determination of cis and trans-permethrin and piperonyl butoxide in a shampoo formulation is described and fully validated. This method entails the quantification of both components by external standard and ultraviolet detection at two wavelengths (201 and 287nm). A C8 Lichrosorb column and a three component mobile phase, isocratically delivered was used.