A fast, sensitive, and selective method for the determination of histamine in human urine samples by ultrahigh pressure liquid chromatography (LC) with fluorescence and mass spectrometry (MS) detection is investigated. A fluorescent reagent, 4-(1-pyrene) butyric acid N-hydroxysuccinimide ester was conjugated to the primary and secondary amino moieties of histamine. The structure of dipyrene-labeled histamine in human urine was determined by quadrupole time-of-flight MS with electospray ionization interface. The determination of the dipyrene derivative of histamine in urine samples was achieved within 3.9 min on an ultrahigh pressure LC Eclipse Zorbax XDB-C18 column with 1.8 mu m particle diameter. In this work, histamine separation was achieved significantly faster (3.9 min) with improved detection limit (signal-to-noise=3) of 0.04 nM than 19.5 min with a detection limit of 0.183 nM as reported in a previous method.