We investigated an electroless aluminum plating based on using AlCl3-1-ethyl-3-methylimidazolium chloride (AlCl3-EMIC) ionic liquid with diisobutyl aluminum hydride (DIBAH) as a liquid reducing agent. The plating film was analyzed by measurements of X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) and glow discharge optical emission spectroscopy (GD-OES). Consequently, a thick aluminum plating film with high uniformity was prepared from AlCl3-EMIC with DIBAH. No impurity phases were detected. Moreover, we discussed the reaction mechanism of the electroless aluminum plating. (C) 2009 Elsevier Ltd. All rights reserved.