We have studied the structural and magnetic properties of thin films of ZnO and GaN semiconductors doped with magnetic and non-magnetic transition-metals. The films were prepared on sapphire substrates by pulsed laser deposition from doped ceramic targets. Room temperature ferromagnetism was observed in ZnO (doped with Sc, Ti, V, Fe, Co or Ni) and in Mn-doped GaN films. In both cases, single crystal epitaxial growth was observed. The higher dopant:Zn ratio observed in the films is attributed to the preferential sputtering of Zn by energetic ions in the laser ablation plasma plume. (c) 2005 Elsevier B.V. All rights reserved.