A novel design was implemented to segment a proton exchange membrane fuel cell (PEMFC) in the land-channel direction to measure the current density distribution at sub-millimeter resolution of 340 mu m. This design was, validated by performing an ex-situ electrical resistance test, in-situ hydrogen pumping test, and by comparing performances between non-segmented and segmented cells at two different conditions. Further, this design was utilized to measure the current density distribution in wet conditions, in extremely dry condition, and in moderate condition. In wet conditions current densities are found to be higher in the channel areas than hi the land areas. To differentiate between the effects of transport distances from-channel to the catalyst layer and non-uniform water saturation distribution in gas diffusion medium, oxygen concentration ratios were estimated in wet conditions. Predicted oxygen ratio distribution showed that the effect of water accumulation under the land in gas diffusion medium is more significant than the effect of transport distance which can be well supported by in-situ microscopy study published in literature. However, in dry condition, current density was higher in the land areas than in the channel while in moderate condition current density was found to be uniform. (C) 2015 The Electrochemical Society. All rights reserved.