Objective: Evaluation of diuretic activity of ethanolic extract of cassia auriculata seeds. Methods: ethanolic extraction of the plant by maceration and the parameters tested during the experimental on each mouse were: total urine volume and the concentration of sodium, potassium, and chloride ions in urine. Results: it showed diuretic activity by inhibiting tubular reabsorption of water and anions. Conclusion: From the results it is evident that, the crude ethanolic extract of Cassia auriculata seeds is safe to use as a diuretic.