Earthquakes hazard probabilities were performed for the broader area of the gulf of Corinth. Related parameters, characteristic of the seismic history of the examined area, were obtained. The probabilities of strong and catastrophic earthquakes with magnitudes Mw>5.5 and Mw>6.0, within 20- and 50- year period were also determined. For this purpose the whole area is divided in cells 0.2ºX0.1º. The obtained results show that there is a very dangerous zone (high probabilities), which starts from the city of Patras and ends to the gulf of Itea, where the estimated probabilities are either very high or high. The highest values observed in cell 39, where for 20-years period and for Mw>5.5 the probability is 77%, while for the same time period and for Mw>6.0 the probability is 42%. Moreover for the time period of 50-years and for the corresponding magnitudes the probabilities are 97% and 74%, respectively.