Abstract Background: Caesarean section is the commonest opera-tion performed by the gynecologists and due to the risks and benefits of ERC and VBAC, cases selection and counseling are of out most importance. Aim of Study: To evaluate inter method and inter observer reliability of 2D versus 3D trans abdominal sonography for lower uterine segment measurement. Method: The study enrolled 100 pregnant women under going elective lower uterine segment caesarean section, all sonographic examination was performed by an ultrasound Voluson E6 BT16 Transducer for 2D and 3D trans abdominal sonography, inner myometrial thickness and full thickness will be measured at the thinnest portion and perpendicular to the contour of the lower uterine segment, then measurement intra operatively using graduated sound. Results: Lower uterine segment inner and full diameter measurements were strongly and directly correlated by both 2D and 3D ultrasonography which means the 3D method of assessment added no more value. Both 2D and 3D method of assessment were correlated to a lower uterine segment meas-urement intra operatively with a comparable correlation factor. Conclusion: Multiple caesarean section patients had a significant lower value of lower uterine segment thickness by all means of measurements.