Background: Induction of labour is common in clinical practice and is usually troublesome in primigravidas. Obestatricians are always in search of the best method of induction to ensure the best maternal and fetal outcome. Objectives: to evaluate the effect of dexamethasone on labor outcome and to establish whether dexamethasone plays a role in shorting of the duration interval between initiation of labor induction and beginning of the active phase of labor in primigravida late-term pregnancy. Patients and methods: Case control study included 120 primigravidae with late-term pregnancy classified into two groups: group I (cases) included 60 women assigned to receive a single 8-mg dose of dexamethasone intra-muscular and group II (control) included 60 women will not receive dexamethasone or any other cervical ripening agent. Results: The interval between initiation of labor induction and beginning of active phase of labor was shorter in the dexamethasone group than in the control group (2.54 ± 0.94 hours vs. 3.59 ± 0.86 hours; p=0.001). Dexamethasone group showed shorter duration of active phase of labor than control group (4.82 ± 0.56 hrs. vs. 5.12 ± 0.58 hrs.). Dexamethasone group showed shorter duration of first stage of labor than control group (7.35 ± 1.15 hrs. vs. 8.69 ± 1.09 hrs.). Dexamethasone group showed faster rate of cervical dilatation than control group (1.37 ± 0.18 cm/hr. vs. 1.28 ± 0.17 cm/hr.). Dexamethasone group showed shorter duration of second stage of labor than control group (25.09 ± 12.99 minutes vs. 30.73 ± 12.96 minutes). Conclusions: The administration of dexamethasone shortened labor duration with no significant difference between the two groups involving the duration of the third stage of labour, the neonatal outcome (meconium stained liquor, Apgar score at 1 minute and 5 minute birth weight, neonatal admission to neonatal intensive care unit and number of cases with fetal heart rate disturbance) and maternal complication.