Management of both cold and hot airflow paths is crucial for energy efficient cooling of servers in data centers. Containment of cold and hot aisles can provide separation between these two streams; however, air leakages from these systems can affect their effectiveness. This paper with the help of a virtual test setup developed using Computational Fluid Dynamics (CFD) simulations describes the impact of leakage area, supply air ratio, and rack cooling load on the performance of hot aisle containment system. These analyses provide valuable insights into the operation of hot aisle containment systems and indicate the leakage areas have the largest impact on the performance of such systems. Increase in the leakage area increases the rate of air leakage and resulting loss in the cooling capacity of the supply air. In addition, the nature and location of leakage paths can affect the airflow patterns and the cooling performance of hot aisle containment systems. Increasing the supply airflow rate as a mitigation strategy does not help in reducing the air leakage rates. Rack cooling loads have little impact of on the rate of air leakage from hot aisle containment. This study demonstrates CFD analysis can be a valuable tool in gaining insights into the design and operation of the hot aislecontainment systems.