[en] The design basis ground motion of a site is generally specified in terms of the peak ground acceleration (PGA), ground motion response spectrum and time history. The probability of exceedence of the design level PGA is one of the factors to quantify the seismic risk at the given site. The present paper extends the work of Cornell to consider an aerial source model and a more general form of the correlation for PGA to evaluate the seismic hazard. It is further recognised that the predicted seismic hazard can vary with various parameters involved. Numerical results have been presented to show this variability. These results will help to determine the seismic hazard at a given site and the associated uncertainties. (author)