Hydralazine (1-hydrazinophthalazine) is used as a vasodilator in the treatment of hypertension. Many analytical methods have been reported for the determination of hydralazine such as atomic emission spectrometry [1], fl uorimetry [2], spectrophotometry [3] and electroanalytical [4]. However, many of these methods need expensive, complicated instruments, and time consuming procedures for preparation of proper derivatives of the analyte.