A reverse phase high performance liquid chromatographic method has been developed for the simultaneous determination of six pyrethrin esters, piperonyl butoxide (PBO), dipropyl pyridine-2,5-dicarboxylate (MGK 326), and endo- and exo-N-octyl bicycloheptene dicarboximide (MGK 264) in pet shampoo formulations. A C8Octyl reverse phase column and different compositions of acetonitrile, methanol and water as mobile phases were used. The eluent was monitored with UV absorption at 220, 230, 240 and 225 nm. Internal standard calculations using peak area was used to calculate each active ingredient peak. Interfering inert ingredients were separated from all active ingredients using this method. This simple and reliable technique has an advantage over GC because of the thermal degradation of pyrethrins, and over normal phase high performance liquid chromatography, since it requires no further sample clean-up.