A fast capillary electrochromatographic method was developed for the analysis of paraben preservatives in drugs and cosmetics in the presence of their main metabolite and/or impurity, 4-hydroxybenzoic acid. The separation was optimized in a 75 pm ID capillary, fully packed with 5 mum C18 stationary phase, studying the effects of mobile phase pH and composition (buffer type and organic solvent content). The mobile phase 5 mM ammonium formate, pH 3.0, containing 65% acetonitrile allowed us to obtain the baseline separation of methyl-, ethyl-, propyl-, butyl-, and benzylparabens from a mixture in less than 2.5 min with repeatability and linearity using the short-end injection method (8 cm separation capillary effective length). Under the optimum experimental conditions, the method provided high separation efficiency for parabens, in the range of 129312-140325 number of theoretical plates per meter, and analyte quantitation limits (LOQs) in the range of 1.25-2.50 mug/mL. The method was successfully applied to the quantitative analysis of paraben preservatives in pharmaceutical and cosmetic industrial samples with direct injection or after reduced sample pretreatment.