After the earthquake of 1980 in Irpinia the Italian Government promoted a damage survey, with the cooperation of researchers of the “Progetto Finalizzato Geodinamica, Consiglio Nazionale delle Ricerche PFG-CNR.” The data of the damage survey have been used in several studies during previous years, and in the present work they have been elaborated on with the aim of assessing a value of the seismic excitation in each administrative unit according to the Parameterless Scale of Seismic Intensity (PSI) (Spence et al., 1991). The PSI intensities are in good correlation with the values of the MSK scale: for each degree of the latter, the PSI intensity, a continuous variable, shows a spectrum of values. At the same time, a model for damage prediction has been identified, where the frequency of a damage degree in a territorial unit is a function of PSI. The proposed damage prediction model has been compared with the Damage Probability Matrix method and the range of variation of the losses evaluated in scenario analyses at the National Seismic Survey has been estimated.