Objective: To evaluate by Ultrasound the lower uterine segment thickness of women with previous Cesarean section delivery determine critical above with safe vaginal delivery is predictable. Patient and Method: The study done in AL-Zahraa Teaching Hospital in AL-Najaf; attachment of Kufa university department of Obstetric and Gynecology. Kufa, Najaf. Among 200 patients with previous lower segment Cesarean section, Ahistory taken including gestational age, the interval between the pregnancy and previous Cesarean section, causes of previous Cesarean section and if it is emergency or elective. Ultrasound finding for this pregnancy including gestational age, lower segment uterine thickness. Result: In this study successful vaginal birth after Cesarean section = (59 %) elective second Cesarean section delivery (10 %) . failed trial of labour (30 %) uterine rupture scar ( 1% ) that is mean only two patients get rupture uterus among 200 patients. Conclusion: Ultra sound evolution permit better assessment of risk of scar complication intra partum could allow for safer management delivery