A quantitative analysis of the image charge effects in dusty plasmas is presented. It is emphasized that the electrostatic interaction caused by the induced charge on grains can play an important role in dusty plasmas even in the case when in the equilibrium dust grains are not charged. As an example, the behavior of the ion electrostatic perturbations propagating in a plasma containing static and neutral (i.e., uncharged) dust grains is examined. A dispersion equation describing a dispersive and always unstable ion wave is obtained. Both the wave dispersion and the instability are a direct consequence of the image charge effect. (C) 2004 Elsevier B.V. All rights reserved.