Emergency department (ED) is a complex system that falls under the category of acute healthcare institutions where health services are provided intensively regardless of the unknowingness of the severity of the medical cases and their spontaneous arrivals. Accordingly, developing a simulation model that exhibits the incurred interactions in ED will lend a hand in supporting the management of the ED in dealing with all those uncertainties. The model performs as a decision-making tool addressing the randomness nature of such an environment. Agent-based modeling simulation was preferred to model the interaction of ED elements using a computer language called Netlogo. And this selection was agreed upon after considering several literature reviews. The ED of Sultan Qaboos University Hospital was monitored, and the medical staff was also interviewed too to gain the required information to build up the model. A conceptual model of the ED was formulated Then, a simulation model was developed.