A review is presented for two-phase modeling approaches to study various transport processes and reactions in polymer electrolyte membrane (PEM) fuel cells along with some experimental work. It has been noted that water management is still one of the least accurate modeled phenomena. The lackness in complete descriptive models for water management inside PEM fuel cells can be attributed to the complexity of the phenomena, lack of empirical or measured data and non-availability of apt governing equations. Another discrepancy found in present models is the proper validation of the numerical work as it has been observed that mere comparison with V-I curve can sometimes lead to misguided conclusions. Additionally, keeping in mind the multi-scale nature of a PEM fuel cell. application of the Lattice Boltzmann (LB) method has also been reviewed in this work and it was noticed that LB methods offer bright perspective at meso-scale by incorporating details of local structure. Furthermore, a brief description of the catalyst layer models is also presented with some technological developments at nano-scale to improve the physio- and electro-chemical properties. A test case for a 2D PEM cathode is also simulated for different operating voltages to predict the water saturation effects. (C) 2011 Elsevier B.V. All rights reserved.