Objective: To assess the estrogenic activity of hydroalcoholic extract of Clitoria (C.) tatea leaves in female Wistar rats.Methods: Hydroalcoholic extract of C. tatea leaves prepared by using cold maceration method was tested for estrogenic activity. An acute toxicity study was conducted to estimate the safe dose using OECD 423 guidelines. For estrogenic activity, ovariectomized female rats were divided into four groups, with 6 rats in each group. The control and standard groups were administered with 1％ carboxymethyl cellulose orally and estradiol valerate at 1 μg/rat/day subcutaneously, respectively. The third group was administered with hydroalcoholic extract of C. tatea at the dose 500 mg/kg body weight orally and the fourth group was administered with hydroalcoholic extract of C. tatea at the dose 500 mg/kg body weight orally along with estradiol valerate at dose 1 μg/rat/day subcutaneously. All treatments lasted for 7 consecutive days and estrogenic activity was assessed by observing vaginal cfication. On day 8, all animals were sacrificed and uterine hs were dissected out. Utrine weight was measured and blood serum was further processed for the estimation of biochemical parameters like cholesterol, total proteins, alkaline phosphatase and estrogen by autoanylser. Histological studies of uterus were also carried out. Results: Acute toxicity studies indicated the hydroalcoholic extract of C. tatea leave was found to be safe up to the dose level of 2000 mg/kg. Oral administration of C. tatea extract at the dose 500 mg/kg body weight and and estradiol valerate (1 μg/rat/day) caused morphological changes i.e. increase in uterine weight, vaginal opening and cification of cells; biochemical changes i.e. increase in cholesterol, total protein, alkaline phosphatase and estrogen contents; histological changes i.e. increase in uterine diameter, thickness and height of endometrium. Simultaneous administration of C. tatea extract with estradiol valerate showed a synergistic effect. Histological investigations further confirmed the strong estrogenic nature of C. tatea extract. Conclusions: C. tatea extract (500 mg/kg) showed a significant estrogenic activity which is also supported by biochemical and histological studies. So, on the basis of these findings, it can be concluded that C. tatea can be used as an altative to synthetic oral contraceptives.