Aqueous and alcoholic extracts of Sida spinosa leaves were tested for diuretic activity in rats. The parameters studied on individual rat were body weight before and after test period, total urine volume, urine concentration of Na+, K- and Cl-. In the present study alcoholic and aqueous extracts of Sida spinosa leaves (100mg/kg of body weight) showed increase in urine volume, cation and anion excretion. Furosemide was used as reference diuretic.