Water management in a Proton Exchange Membrane Fuel Cell (PEMFC) is of great concern for effective cell performance. Existing studies for scaled up model of PEMFC are limited only to experimental work where effective water management with respect to flow channels are very few, time consuming and less economical. In this connection, an extensive numerical study is carried out for optimizing the flow channels with respect to optimal pressure drop and water management for the scaled up model (225 cm2) of PEMFC which is a novel approach in the field of PEMFC. This numerical study involves four different configurations of flow channels. In the first configuration, predominantly existing serpentine parallel flow channel for 25 cm2 is extended to 225 cm2 cross-sectional area. Serpentine zig-zag, straight parallel and straight zig-zag are the other three flow channels considered respectively in this study. The three dimensional flow through the PEMFC is simulated by solving the governing principles namely mass, momentum, energy, species and electro-chemical equations. It is found that the power density developed by straight flow channel with zig-zag flow path is 0.3758 W/cm2 and is the maximum of the configurations considered and this is due to effective water management with minimal pressure drop. © 2016 Elsevier Ltd