The development and application of a new hydrodynamic electrochemical device is described. This novel technique is based on a microwire electrode with approximate dimensions of 25 mu m, sited centrally within a rectangular duct (of 800 mu m height and 0.05-0.02 m width), subjected to fluid flow under well-defined mass transport conditions. Finite element simulations are presented to model the solution velocity profiles within the cell and around the microwire electrode. The results of these calculations were employed to characterize the concentration distribution of a reactant within the cell, which is undergoing a transport-limited reaction at the electrode/solution interface. Experimental studies using the new technique were performed using aqueous and organic solutions containing ferrocene and potassium ferrocyanide to establish the variation of electrolysis current as a function of the solution flow rate. The experimental results are compared to those predicted numerically and good agreement is noted.