A sensitive and quick measurement of Nitric Oxide (NO) in real time is described using differential pulse voltammetry in aqueous solution. NO is estimated over electrochemically deposited polycarbazole conducting polymer modified platinum minielectrode of 0.0078 cm(2) geometrical area in deoxygenated 0.1 M phosphate buffer (pH 7.4) at 25 degreesC, NO oxidation peak is observed during anodic scan at 0.65 V vs, Ag/AgCl. A linear dependency between NO concentration and anodic peak current is obtained in the standard addition of NO from 10 nM to mM range. The interference with ascorbic acid and dopamine are found to be negligible over polycarbazole modified electrode.