Isaño and cola de caballo are used in Bolivia for their traditional use as a diuretic, but there are nopharmacological studies that confirm this effect. Objective: to determine the diuretic effect of theaqueous extract of isaño and cola de caballo. Methodology: male mice were used, which were dividedinto four groups, a positive and negative control and two dose groups (D1 and D2) of the extract. Bothdried plants were fractionated for the preparation of the aqueous extract, with which the preliminaryphytochemical screening was carried out, and the technique described by Lipschitz was carried out todetermine the diuretic effect. Results: The phytochemical analysis revealed the presence of flavonoidsfor the aqueous extract of cola de caballo. And the aqueous extract of Isaño showed the presenceof tannins, anthocyanins and flavonoids. The highest volume of urine collected was for the posi...