This paper uses a PSOPC model based non-destructive damage identiﬁcation procedure using frequency and modal data. The objective function formulation for the minimization problem is based on the frequency changes. The method is demonstrated by using a cantilever beam, four-bay plane truss and two-bay two-story plane frame with different scenarios. In this study, the modal data are provided numerically using the ﬁnite element method. The effectiveness of using frequencies as the data for quantiﬁcation of damage severity and location are checked. The effects of noisy incomplete data on the accuracy of damage detection with PSOPC algorithm are also discussed.