Sandwich honeycomb panels are widely used in aerospace applications because they are very light and stiff. Strong mechanical or acoustical excitations, associated to low damping properties of such panels can lead to high vibration levels, generating fatigue and reliability problems. We propose in this paper to investigate the capability of micro-perforations of honeycomb panels for reducing their vibration levels. Micro-perforations are mostly known and used in acoustics for increasing absorption. A model of the panel vibration damping induced by the acoustic motion in the micro-perforations is proposed here. For this purpose, a lumped element model, based on Maa's results is developped for estimating a viscous damping force at the micro-scale. The resultant force is then homogenized for a group of cells (meso-scale model) and allows us to express a damping term for the global structure (macro-scale model). A perturbation technique is then used to compute the modal damping coefficients of a micro-perforated plate in order to evaluate the performance of the treatment.