Abstract: Cyclic voltammetry (5 mV s-1 scan rate, 50 mV amplitude) was used to characterize the electrochemical behavior of nicardipine(I) with vitreous-carbon, carbon-paste and hanging-mercury-drop electrodes. I was shown to be adsorbed on carbon electrodes with the surface species retaining its electroactive characteristics. This accumulation serves as a concentration step, improving the selectivity and sensitivity of the measurements. By removal of the electrode from the sample, after accumulation, and re-immersion in a second cell containing an electrolytic blank solution, interferences due to solution-phase electroactive compounds are eliminated and direct measurement is possible in urine. Differential pulse voltammetry at the mercury electrode permits determination of <1 µM-I with a detection limit of 20 nM. Amperometric detection for a flow injection system is shown.