Objective To investigate the effect of ethanolic and water extracts of the leaves of Gnetum africanum on the morphology of uterine smooth muscles of rats. Methods Three tolerated doses of the extracts, 10 mg/kg, 200 mg/kg and 700 mg/kg per day, were obtained from the results of acute toxicity test and administered orally to three respective groups of female rats for 3 d and saline group of rats served as the negative control (0 mg/ml), 17β estradiol group of rats served as the positive group, 5 rats per group. Rats from each of the groups were sacrificed on the 4th day and their uteri were carefully isolated and examined. Results The study revealed that both extracts of the leaves of Gnetum africanum influenced the uterine muscle weight and growth of both adult and immature female rats in a similar manner as 17 β-estradiol. Conclusion The leaves of Gnetum africanum may be phytoestrogenic and could influence fetal implantation or ova fertilization, therefore, abuse in the use of the leaves of Gnetum africanum as vegetable in some Nigerian meal. Meanwhile this effect is reversible, the plant-extracts could be possibly developed as a female contraceptive to control birth rate. Objective To investigate the effect of ethanolic and water extracts of the leaves of Gnetum africanum on the morphology of uterine smooth muscles of rats. Methods Three tolerated doses of the extracts, 10 mg / kg, 200 mg / kg and 700 mg / kg per day , were obtained from the results of acute toxicity test and administered orally to three respective groups of female rats for 3 d and saline group of rats served as the negative control (0 mg / ml), 17β estradiol group of rats served as the positive group , 5 rats per group. Rats from each of the groups were sacrificed on the 4th day and their uteri were carefully isolated and examined. Results The study revealed that both extracts of the leaves of Gnetum africanum influenced the uterine muscle weight and growth of both adult and immature female rats in a similar manner as 17 β-estradiol. Conclusion The leaves of Gnetum africanum may be phytoestrogenic and could influence fetal implantation or ova fertilization, therefore, abuse in the use of the l eaves of Gnetum africanum as vegetable in some Nigerian meal. Meanwhile this effect is reversible, the plant-extracts could be developed developed as a female contraceptive to control birth rate.