In　this　paper,　the　pressurized　capillary　electrochromatography　(pCEC)　with　UV　detection　was　utilized　for　the　separation　and　determination　of　three　structurally　related　estrogens,　such　as　diethylstilbestrol　(DES),　hexestrol　(HEX)　and　dienestrol　(DE),　which　were　difficult　to　be　separated　by　capillary　electrophoresis　(CE)　and　HPLC　due　to　their　similarity　in　the　structure　and　charge-to-mass　ratios.　Experiments　were　carried　out　in　a　commercially　available　pCEC　instrument　using　a　capillary　column　packed　with　3　μm　octadecyl　silica　(ODS).　Surfactant　sodium　dodecyl　sulfate　(SDS)　was　introduced　in　the　mobile　phase　to　enhance　the　speed　of　analysis.　The　effective　factors　on　the　retention　time　and　separation　resolution,　such　as　the　applied　voltage,　supplementary　pressure,　the　pH　and　the　concentration　of　the　buffer　solution,　the　concentration　of　SDS,　and　the　content　of　acetonitrile　in　the　mobile　phase,　were　evaluated.　Based　on　the　investigation,　31%　(v/v)　acetonitrile　and　69%　(v/v)　of　10　mmol/L　phosphate　buffer　(pH　6.5)　containing　1.0　mmol/L　SDS　at　an　applied　voltage　of　-12　kV　and　a　supplementary　pressure　of　1000　psi　were　found　to　be　the　optimal　conditions　for　pCEC　to　separate　the　three　estrogens.　The　method　also　had　been　applied　to　the　analysis　of　fish　muscle　samples　spiked　with　estrogens.　©　2005　Elsevier　B.V.　All　rights　reserved.