The virtual fields method (VFM) is used as an inverse procedure to process curvatures obtained from full-field measurements for the identification of the local loss of stiffness in composite plates. The VFM has been adapted to the case of a plate with stiffnesses varying spatially. Two parameterization methods for the stiffness reduction were developed: continuous (polynomial) and discrete (piecewise). In this study, the procedure is described, validated on simulated data and several experimental results are given. The method not only picks up the location of the damage but also provides a fairly good estimate of the stiffness reduction in the damaged area when the through-thickness displacement distribution in the damaged region is reasonably linear.