Anatase and rutile TiO2 were investigated as stable supports for different multimetallic nanoparticles (i.e., Pt:Ru, Pt:Ir, Pt: Ru:Ir, and Ir:Ru) and tested for activity toward the oxygen evolution reaction (OER). Overall, Ir: Ru had the highest activity toward OER (i.e., current per gram of metal) compared to the other multimetallic combinations studied. This bimetallic supported on anatase TiO2 had a 53% higher current per gram of metal than an unsupported electrocatalyst of the same composition. The higher catalyst utilization of the supported electrocatalysts for OER is consistent with small, well-dispersed nanoparticles, which were observed in high resolution transmission electron microscopy images. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3528163] All rights reserved.