A novel system for measuring local currents in polymer electrolyte fuel cells (PEFCs) has been developed. It has the advantages of a magnetic loop array and allows an easy and highly flexible implementation. This communication deals with our experience and the principle of measurement of this diagnostic method for the current mapping of PEFCs. The feasibility of this approach is demonstrated on a small-scale single-cell direct methanol fuel cell (DMFC). The impact of the operating conditions such as air stoichiometry or anodic flow rate on the current distribution of such a DMFC is discussed. (C) 2004 The Electrochemical Society.