Both probabilistic and deterministic methods have a role in seismic hazard and risk analyses performed for decision-making purposes. These two methods can complement one another to provide additional insights to the seismic hazard or risk problem. One method will have priority over the other, depending on how quantitative are the decisions to be made, depending on the seismic environment, and depending on the scope of the project (single site or a region). In this study, seismic hazards in Shiraz and adjacent areas were analyzed mainly on the basis of geological fault data. We identified 3 active fault zones derived from both active fault data and earthquake catalogues. Both deterministic (DSHA) and probabilistic (PSHA) approaches were used—DSHA for the design of critical construction and PSHA for the design of non-critical construction. The seismic hazard results obtained using the deterministic and probabilistic approaches are equivalent. The resulting DSHA and PSHA maps reveals extremely high seismic hazard levels in some areas of Shiraz and in surrounding cities. The areas of high seismic hazard include cities neighboring Shiraz, such as Marvdasht, Kazeroon, and Abadeh, and areas within Shiraz itself, primarily those areas in northern, western, and southern Shiraz that are dominated by active fault zones.