The magnitude-frequency relationship of earthquakes has been investigated in view of its applications in seismic hazard assessment. For areas, where earthquake occurrences are frequent, the magnitude – frequency relationship can be established on the basis of regression analysis. For other areas, where earthquake occurrences are infrequent, quantification of seismicity has to be based on some assumptions and theoretical models. Application of the extreme event method helps in arriving at some estimates, which are verifiable in a few cases. This application is discussed in detail to illustrate method, which could be adopted for dealing with situations of inadequate data.