The cathode design is one of the most important parts in order to enhance the performance of fuel cells. A 3-D model of the porous oxygen reducing cathode with perforated current collectors is analysed for the enhanced design in fuel cells. Simulation is performed using equations of electric potential balance, momentum balance, and mass balance. The gas concentrations are quite large and are significantly affected by the reactions that take place. The weight fraction of oxygen, velocity field for the gas phase, and local overvoltage are illustrated in the porous reactive cathode layer. The current density is also analysed and the result shows the distribution and variation are stated in a wide range. It is found that the rate of reaction and the current production is higher beneath the orifice, and decreases as the distance to the gas inlet increases. The significance of the results is discussed in the viewpoint of the mass transportation phenomena, which is inferred that the mass transport of reactants dictates the efficiency of the electrode in this design and at these conditions.