In the Performance-Based Seismic Design framework, the development of an appropriate “Probabilistic Seismic Hazard Analysis” which allows to statistically characterize the seismic input at the site of an engineering project becomes of crucial importance. The objective of the hazard analysis is to compute, for a given site over a given observation time, the probability of exceeding any particular value of specified ground motion parameters. This paper proposes a new hazard analysis procedure which is based on the same assumptions of the Cornell’s widely upheld approach, but is alternative to this. The peculiarities of the pro-posed procedure resides (i) in that it leads to the determination of the probability functions (CDF and PDF) of the selected ground motion parameter (PGA, PGV, ...), and (ii) in that the occurrence of seismic events may be schematized either with the widely-used Poisson process or with more general Non-Poissonian models.