The incident fluence is shown to be an effective parameter in controlling the diameters of ZnO nanorods grown by pulsed excimer laser deposition following ablation of a ZnO target in low background pressures of oxygen. The evolution in nanorod diameter and the overall sample morphology with incident fluence is rationalised by considering the bombardment effect of high energy species in the plume formed in the ablation event. (C) 2007 Elsevier B.V. All rights reserved.