Background: The degree of the lower uterine segment (LUS) thinning and the risk of uterine scar defect have been studied. However, the relationship between the methods of closure and the degree of thinning needs further elucidation. Aim: The aim of this study was to determine whether a LUS transverse cesarean section (CS) closure method in one or two layers affects subsequent scar thickness. Subjects and Methods: In this prospective study, 150 women were enrolled and randomly assigned to one‑ or two‑layer closure of the LUS incision. Patients were divided into two groups. Each group included 75 patients, of primigravidae with gestational age from 38 weeks to 40 weeks one group had a single layer closure and the other had a double layer closure. Results: We found an increase in the thickness of LUS‑CS scar in cases with double layer closure of the incision than a single layer closure as depicted by ultrasonography after 2 days and 2 weeks post‑operative. Conclusion: These findings suggest that the number of closing layers of CS directly affect the thickness of the scar.