Introduction: Decision making about the location of emergency medical centers, to facilitate quick respond to requests for emergency medical services, is a complex issue for managers of emergency medical services. This research aimed to reduce the response time to emergency medical services requests, using a combination of optimization and simulation methods for placement of emergency bases. Methods: This was a descriptive research. A number of locations in the districts one, three, five, and six of Isfahan City, Iran, were defined as the locations of emergency medical bases, according to criteria such as population density, and the rate of request calls for emergency medical services. Then, the final locations of bases were determined among these possible locations. After determining factors such as the impact of traffic conditions on response time, demand rate, and operating costs, different scenarios were analyzed using Arena software, and the best scenario was selected. Results: The mean time of response to emergency requests reached nine minutes, with the implementation of the selected scenario, which was close to the international standard of eight minutes. Conclusion: The results of this research show that without spending a lot of money to create and equip additional bases, different requests can be answered in the shortest possible time. The method presented in this study can be used to solve placement problems of other emergency services such as firefighting stations.