An effective approach to attach gold nanoparticles (AuNPs) directly on indium, tin oxide (ITO) surface with higher density is reported. The attachment was carried out using a cast seed-mediated growth method, which was revised from our previous seed-mediated growth approach. The cast seeding with three-cycles of the drop of the seed solution containing Au nano-seed particles and the evaporation at 30 degrees C followed by the treatment in the growth solution containing HAuCl4, cetyltrimethylammonium bromide (CTAB) and ascorbic acid was found to be suitable to prepare the AuNPs attached ITO surfaces having higher density and narrower size distribution. The 10-cycles cast seeding formed the connected or networked nanostructures of AuNPs, though the optical properties were different from those of the dispersed AuNP-attached ITO. The present cast seeding approach provides a facile and useful strategy to attach AuNPs on the surface without the use of certain organic binder molecules. (c) 2006 Elsevier B.V. All rights reserved.