This letter is aimed at presenting results confirming the contribution of polarimetry to improve the performance of persistent-scatterer interferometry. The improvement is provided by the identification of more pixels with good phase quality, under criteria commonly employed in this context, after a search in the available polarimetric space. The ground deformation results obtained with a series of 41 dual-polarization images acquired by TerraSAR-X over the metropolitan area of Murcia, Spain, have been used to illustrate this approach.