Effect of common optoelectronic dopants like In, Sb and Ga on the structure, morphology and vibrational modes of ZnO nanostructures has been studied systematically using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. While incorporation of Ga has no strong effect on the lattice parameters and crystallinity of ZnO nanostructures, In and Sb doping introduce considerable lattice distortion. Sb doping results an anisotropic distortion along the c axis of the ZnO unit cell. Several anomalous vibrational modes are induced due to incorporation of dopants into ZnO lattice. Origins of the observed anomalous modes are discussed. (C) 2010 Elsevier B.V. All rights reserved.