In this work the Greek seismicity is being investigated by means of Non-Extensive Statistical Physics [NESP]. NESP is a generalization of Boltzmann-Gibbs statistical physics and has been successfully used for the analysis of a variety of complex dynamic systems, where fractality and long- range interactions are important. We use a non-extensive model that is derived from the first principles to describe thefrequency-magnitude distribution of the Greek seismicity for the period 1976-2009 by using a recent earthquake catalogue for the Hellenic region compiled by Makropoulos et al. (2012). The results indicate that the non-extensive model can describe quite well the observed magnitude distribution for the entire magnitude range. Furthermore, the q parameter of the non-extensive model, along with the bvalue of the Gutenberg-Richter relation, are being estimated for different time windows along the time expansion of the catalogue and the variations of these values are being discussed.