2,4,5-Triarylimidazoles have been obtained in excellent yields by the one-pot three-component condensation of bis-aryl alpha-hydroxyketones, aromatic aldehydes and ammonium acetate by the action of inexpensive, readily available and nontoxic KMnO4/CuSO4 under mild reaction conditions. The present method is simple, efficient, cost-effective and eco-friendly.