Open AccessThe purpose of this article is to evaluate the diuretic potential of Rubus idaeus L. fruits. By measuring the urine volume of experimental animals, we find that methanol extract of Rubus idaeus L. fruits significantly increased the urine volume of experimental animals suggesting its diuretic effect. This is the first formal report on the diuretic activity of Rubus idaeus L. fruits. Moreover, four fractions isolated from the methanol extract were further studied and the results showed that ethyl acetate fraction (RIEA) has a direct relationship with the diuretic activity of Rubus idaeus L. fruits. The urinary electrolyte patterns of experimental animals were also analyzed, we find that Rubus idaeus L. fruits have an effect on the conservation of potassium, which is an interesting property in a phyto-diuretic.