Fire safety in underground car parks is a major concern during the design project phase, as well as construction features, such as the inexistence of openings to help ventilate the space, can promote dangerous situations in case of a fire. Difficulties during the evacuation process may arise due to poor visibility conditions, rapid temperature rise and possible smoke inhalation. As a result, smoke control/removal systems in underground car parks are mandatory by Portuguese law and their main purpose is to create conditions to safely evacuate the occupants and extract contaminated air from the damaged space. The case under study is based on a fully covered underground car park, equipped with a smoke removal system. To understand the system operation, numerical simulations were carried out. Therefore, by using Computational Fluid Dynamics tools, in this case Ansys Fluent, a representation of the system behaviour was simulated. The purpose of this study is to simulate different fire scenarios in a car park and compare the impact that different fire ignition locations can have on the smoke control system efficiency since certain areas can be more problematic than others. The results obtained allow the analyses of the fire dispersion when the system is activated, indicating critical points in three different scenarios simulated. Regarding the air velocity, the maximum value of 11.3 m/s was reached near the central ventilator, after system stabilization (after 1500 simulation seconds).