Induction of labor is widely carried out all over the world in cases where continuation of pregnancy is hazardous to both the mother and/or fetus. The induction in a ripe cervix is not difficult but complications are significantly increased when the cervix is unripe. The only agent approved for cervical ripening and induction of labor in patients with an unripe cervix is dinoprostone(PGE2). Misoprostol is a synthetic PGE1 analogue marketed for the prevention and treatment of gastro-duodenal ulcers. Misoprostol costs much less than dinoprostone and does not require refrigeration and has few systemic side effects.In addition, it is rapidly absorbed orally and vaginally. Although misoprostol is not registered for such use, it has been widely used for obstetric indications such as induction of abortion and of labor. Misoprostol for induction of labor in preceding literatures mainly prescribed in multiple dosing regimen. The adverse effects on uterus potentially occur owing to the frequent administration of misoprostol. The objective of this study was to compare a single dose oral misoprostol with vaginal misoprostol.