Proton exchange membrane (PEM) fuel cells can be manufactured with different flow field designs, which can affect the performance substantially. The most common types of flow fields are serpentine and parallel flow field configurations. In this study, 3D Computational Fluid Dynamics (CFD) models of the parallel and the serpentine flow fields are simulated. Governing equations and electrochemical phenomena are modelled by ANSYS FLUENT-PEMFC module and temperature, pressure and water vapour distributions inside the flow fields are obtained. According to the oxygen consumption rate, the electrical current values are obtained and, as a result, the serpentine flow field is found to be more efficient than that of parallel flow field.