Context: Moringa stenopetala (Baker f) Cufodontis is an evergreen tree of approximately 5 to 10 m height and widely distributed in the Southern parts of Ethiopia with numerous nutritional and medicinal purposes.

Objective: The aim of the study was to evaluate the effect of hydro-ethanolic extract of M. stenopetala leaves using in-vivo mice model of diuresis.

Methods: Furosemide (10 mg/kg), normal saline (1 ml/100 g), and extract doses (150, 250, 350, 500 and 1000 mg/kg) of body weight were used as standard, control and test substance respectively. All substances were administered orally. The urine output and electrolyte concentration of Na+, K+ and Cl-were determined.

Results: At all doses the experimental group had a significant urine output at 0.5 hour and 1 hour (P< 0.001) compared to standard and control. After 2.5 hours, at 500 mg/kg the extract showed an increased urine output compared to the control as well as the extract doses of 150, 250, 350 and 1000 mg/kg (P< 0.05). The excretion of Na+ and Cl-was significantly increased at 250 and 350 mg/kg test doses (P< 0.001) compared to control. At 500 and 1000 mg/kg, there is a comparable Na+ and Cl-excretion and a significant K+ excretion ((at 500 (P< 0.01) and 1000 mg/kg (P< 0.01)) compared to standard and control respectively.

Conclusion: The outcome of the study demonstrated the diuretic activity of the hydro-ethanolic extracts of M. stenopetala leaves which is in agreement to the folkloric use of the plant for the management of hypertension and heart failure.