Transparent organic light-emitting devices (TOLEDs) were successfully fabricated utilizing a novel transparent conducting cathode with low work function. Cesium-incorporated indium-tin-oxide film was deposited oil the organic layers with negligible damage by simultaneous operation of RF magnetron sputtering using an ITO target and vacuum evaporation of metallic cesium. Incorporation of cesium in the ITO film was confirmed by XPS analysis. The work function (4.3 eV) determined by photoelectron spectroscopy in air (PESA) was lower than that of 0.3-0.4eV without cesium-incorporation and stable under the atmospheric environment. The electron injection efficiency of cesium-incorporated ITO cathode in the present transparent OLED fabricated was comparable to that of the previous double-layered structure comprising of ITO cathode and an organic buffer layer (BCP) doped by evaporation of cesium [T. Uchida, S. Kaneta, M. Ichihara, M. Ohtsuka, T. Otomo, D.R. Marx, Jpn. J. Appl. Phys., 44, No. 9 (2005) L282], (c) 2005 Published by Elsevier B.V.