Room-temperature ferromagnetism has been identified in sol-gel-prepared Co-doped ZnO (ZnCoO), hydrogen being incorporated by a linear polymer polyvinyl pyrrolidone. The magnetic order was investigated by the X-ray photoemission and magnetization measurements in view of the interstitial hydrogen being coupled with Co2+. The electron paramagnetic resonance measurements revealed that hydrogens not contributing to the magnetic order occupy the shallow donor levels in the hydrogenated ZnCoO system. (C) 2013 Elsevier B.V. All rights reserved.