Italy is one of the countries of the Mediterranean Sea most affected by tsunamis. Catalogues of Italian tsunamis show that Italian coasts were attacked by large tsunamis in the past that had catastrophic effects, causing thousands of victims and severe damage. Though the cases of tsunamis associated with volcanic activity and submarine slides cannot be neglected, most tsunamis were the results of coastal and submarine earthquakes. Therefore, assessing the occurrence probability of tsunamigenic earthquakes is an important contribution to the global evaluation of tsunami hazard. Improving a methodology used for a preliminary evaluation of tsunami hazard in Italy more than one decade ago, this paper applies probabilistic seismic hazard techniques focussing on Calabria and Sicily, that are among the most active seismic and tsunamigenic regions in Italy. The estimated tsunami activity, expressed in terms of the number of expected events in a 10,000-year period with run-up heights exceeding a given threshold value, is compared with the information deducible from the most recent Italian tsunami catalogue.