Seismic risk is usually defined as the probability of exceeding a specified level of loss due to earthquakes for a set of goods within a reference period of time. Usually it is measured by considering the convolution of three main factors: hazard (probability of earthquakes), vulnerability (probability of damage, given the earthquake), and exposure (probability of loss given the damage). Thus, the seismic risk in a geographical region depends on many uncertain variables pertaining to the three main factors listed above. Some of the uncertainties are reducible through deeper investigation, while others reflect intrinsic randomness and are therefore unavoidable. Seismic risk assessment (SRA) is very important for public safety and hazards mitigation. It is also important for the correct determination of earthquake insurance premiums, and for understanding the social and psychological effects of earthquakes. This study represents an extensive review and evaluation of SRA methodology. SRA strategy, source parameters, attenuation, and local site effects are explained in detail. Global and national seismic hazard maps relating to seismic risk are presented. A variety of references concerned with the problem SRA are given.