Electrocatalytic oxidation of hydroxylamine on dinuclear ruthenium phthalocyanine (RuPc)(2) modified electrode is studied using cyclic voltammetry (CV) and rotating disc electrode (RDE) techniques. A two-electron oxidation of hydroxylamine to N2O is observed in the pH range of 9-13. A suitable mechanism is proposed by analyzing the rate equation and the Tafel slope. (C) 2003 Elsevier Ltd. All rights reserved.