<p class="Abstract">The aim of this study was to evaluate the diuretic activity of <em>Eysenhardtia polystachya</em> bark aqueous extract at different doses in a rat model. Different doses of <em>E. polystachya</em> (125, 250, 500 and 750 mg/kg body weight), furosemide (4 mg/kg) and vehicle were administered per os to female rats (n=6 animals per group). After 6 hours in metabolic cages, the effect on urinary flow, glomerular filtration rate and electrolyte balance of sodium and potassium were assessed in all animals. <em>E. polystachya</em> at the doses of 500 and 750 mg/kg induced diuretic activity, since markedly increased (p<0.05) the urinary flow rate, similar to that of furosemide treated group. Only the dose of 750 mg/kg produced an increment in urinary excretion of sodium but not of potassium compared with control group. These findings indicate that<em> E. polystachya</em> bark-induced diuretic activity, providing evidence for its folkloric use.</p><p> </p>