This paper deals with an experimental study of mass transfer to thin flow-through porous electrodes placed in a laminar flow. Both situations of a parabolic and a uniform velocity distribution upstream the electrode (nickel foam, sintered nickel, platinum wire gauze, micromesh expanded nickel) are considered. The results are compared with a model encountered in the literature. The model inaccuracy is theoretically and experimentally established. It is shown that for grades smaller than 100 pores per inch, a laminar dow would have to be made hydrodynamically unestablished (uniform).