Background: induction of labor is a common obstetric procedure which is performed for a variety of medical and non-medical indications. If the cervix is unfavourable, prior ripening of the cervix makes induction of labor easier and more succeful. There are different methods for ripening of the cervix and making it ready for induction. These methods included medical methods such as the administration of prostaglandins, and mechanical methods such as extra amniotic saline infusion, traction on the cervix with Foley catheter and laminaria. Aim of the Work: the aim of the study is to evaluate the efficacy of intramuscular dexamethazone injection prior to induction in improving progression and duration of labour phases. Patients and Methods: this study started with 100 Nulliparous Pregnant women who were conducted at the labor wards of Ain Shams Maternity Hospital. The studied subjects were randomized into two groups: Dexamethasone group: This group included 50 Nulliparous women (N=50), called A group.  Control group: This group included 50 Nulliparous woman (N=50), called B group. Results: in this study the duration of active and second stages was decreased without change on mode of delivery. The study no significant statistical differences between the two studied groups as regards fetal heart rate. The duration of second stage in dexamethasone group was shorter than in the control group. Dexamethasone intramuscularly prior to induction significantly shortens duration of normal labor in normal parturants with minimal complications. Conclusion: an intramuscular injection of dexamethasone before labor induction is found to shorten the duration of labor induction by decreasing the interval between the initiation of induction and the beginning of the active phase, duration of active phase and duration of second stage of labor with no observed maternal or neonatal complications.