The effect of a static homogeneous magnetic field that is directed parallel to the planar electrode surface is analyzed in terms of a hydrodynamic boundary layer formation and equivalent mass transfer model for a semi-infinite electrode. The model predicts the decrease of the boundary layer thickness upon increasing either the magnetic field strength, B, or reagent bulk concentration, C*, with the power dependence corresponding to C*B-4/3(1/3). This permits the interpretation of the enhanced mass transfer at electrode surfaces via hydrodynamic principles.