Currently available diuretics are not completely free from side effects such as electrolyte imbalance and metabolic alterations. Avocado (Persea americana Mill.) contained many type of bioactive substances that related to diuretics. This study aimed to reveal and verify the effect of water fraction of avocado leaves extract against output of rat urine. Three different doses of leaf extract of avocado prepared i.e., 91.125mg/kg BW, 182.25 mg/kg BW and 364.5 mg/kg BW. The urinary parameters assessed were the urine volume hourly for 6 hours, urine color density and urine pH. The results showed water fraction of avocado at the dose of 182.25 and 364.5 mg/kg significantly increase urine volume in comparison to the negative control. Urine color density scores varied but did not have a dependent manner that follows the dose levels of diuretics given. However all treatments showed no statistical difference in the urine pH. Thus, it can be conclude that the water fraction of avocado leaves extract potentially for diuretic herb without make significant changes on pH.