An analytical method for the determination of 4-aminophenazone using cyclic and differential-pulse voltammetry has been developed. The oxidation process was shown to be irreversible over the pH range 3.0-11.2. The dependence of the current on pH, concentration, and scan rate was investigated to optimize the experimental conditions for the determination of 4-aminophenazone. The number of electrons transferred in the oxidation process was calculated, and a probable oxidation mechanism was proposed. In the range of (1.0 X 10(-6))-(1.6 X 10(-5)) M, the current measured by differential-pulse voltammetry as a function of the concentration of 4-aminophenazone with a detection limit of 0.458 X 10(-7) M with good selectivity and sensitivity exhibited a good linear relationship. The proposed method was applied to the determination of 4-aminophenazone in a real sample.