AbstractThe effect of an aqueous extract of fresh floral buds ofJasminum officinalevar.grandiflorumLinn. has been studied on female fertility in rats. Parameters included effects on the oestrus cycle, implantation, fetal loss, abortion, teratogenicity and serum progesterone levels on days 5, 12 and 20 of pregnancy. The extract at oral doses of 250 and 500 mg/kg produced a dose dependent significant antiimplantation effect, but failed to produce complete infertility. Treatment of animals during day 8 to day 12 to day 20 of pregnancy did not produce any significant abortifacient activity. There was no significant change in the weight and length of the fetuses delivered by rats treated with extract and no abnormalities were seen in the organs of the offspring. The extract produced a significant decrease in serum progesterone levels on day 5 of pregnancy which may be responsible for the antiimplantation effect observed in this study.