The theme of the work is the development of a simulation model of student enrollment in undergraduate and graduate studies, based on discrete simulations. Discrete simulations are appropriate for this type of process because they allow detailed modelling and analysis of complex systems with discrete events, such as the registration, processing and enrollment of students. There are a number of programs for modelling discrete simulations such as GPSS, SIMSCRIPT, SIMULA and Simul8, and ARENA Simulation will be used in this work. The program ARENA is a simulation software used to model and analyse different types of business and operational systems, i.e. to diagnose and solve business problems, reduce operational costs and improve financial forecasts. This model helps to find innovative solutions and design different scenarios that can reduce the burden on administrative staff and increase student satisfaction. Although the simulation model of student enrollment is being developed for the Faculty of Economics in Osijek, this application can be useful for other faculties in the Republic of Croatia. This paper will address the basic concepts that are key to understanding discrete event simulations such as entities, events, activities and processes. For the simulation model, data were collected and analysed from the website Postani student for undergraduate enrollment and diplomskistudij.hr for graduate enrollment, while for the processes, data were collected from student reports. These data include enrollment quotas which indicate the maximum number of students that can be admitted to the desired study. The work analyses the results obtained from the reports received in the program ARENA and, on this basis, makes recommendations for improving the existing process. The simulation model of student enrollment can be a useful business tool, allowing the regulation of operational costs and the improvement of the overall enrolment process.