The usage of simulations has been improved for quite some time. From mechanical artifacts that attempt to mimic a certain dynamic event using known physical properties up to complete representations of virtual worlds based on real life events which were augmented by concepts in order to prove a theory or to test a specific scenario. The key words here are “modeling”, “constructing a simulacrum”, “experimentation” and “evaluation”. Simulations allow any researcher to explore, try out new ideas, check some theories in a controlled environment before testing in real life, and so forth. Psychology deals with individuals, Sociology with the study of human groups and the formation of institutions, both, individually, were not enough to study the humanSs social behavior. All human sciences tried to create theories about reality, searching for well-defined and established patterns. The non-conformity with such patterns is considered a mistake, or even a wrongdoing. Taking a whole new approach, the field of Collective Behavior deals with human groups and collectivities that contradict or reinterpret societySs norms and standards. Crowd behavior has been studied by many researchers. Theoretical models have been established to understand them. This chapter will present a simulation model for panic in crowds phenomena based on the symbolic interactionism approach. Section 2 will present a review of the main concepts of Sociology and Collective behavior and establish a framework to be used in the model of crowd to be simulated. Section 3 will present a computation model and a simulation model of panic in crowd phenomenon, both in its theoretical aspects and its practical issues. The collective behavior studied in the previous section will be used as basis for the simulation model. Also, the main concepts regarding multi-agent based simulations will be presented. The model simulated have been applied to a fire incident and validated. Section 4 presents a generalization of the model proposed and delineates a future application for other kind of disasters as earthquakes. Section 5 shows some conclusions about the study here presented. 20