Starvation is a vivid word to describe the operation condition of a fuel cell in sub-stoichiometric reactants feeding. In starvation, a fuel cell could not present its best performance; moreover, there might also be safety issue because of cell reversal. In this paper, current density distributions of proton exchange membrane fuel cell (PEMFC) in hydrogen and air starvation were studied with a segmented single fuel cell. Experimental results show that the polarization curves of the overall cell are different for anode and cathode starvation. And the current density distribution results show that for anode starvation, current density of the starved region drops sharply to zero, while for cathode starvation, there is no zero current density region observed. Numerical simulations give similar results. (c) 2005 Elsevier B.V. All rights reserved.