The liquid chromatographic determination of histamine was achieved by precolumn derivatization with N-(4-aminobutyl)-N-ethylisoluminol isothiocyanate and electrochemiluminescence detection. Detection was carried out using postcolumn on-line electrochemical reagent generation and oxidation of the derivatized analyte at a gold gauze working electrode built in the flow cell of the detector. With this on-line method a detection limit of 1.5 pmol (S/N = 3) of histamine was obtained. The method was linear in the range 0.5-10 nmol and the repeatability of the method was satisfactory (R.S.D. = 13.7% and 3.7% at the 0.5 and 5 nmol level, respectively).