OBJECTIVE Comparing locked and unlocked uterine closure techniques in terms of bleeding control and uterine incision healing. METHODS The patients undergoing cesarean section in Sifa University Hospital between May - October 2012 were accepted to this prospective controlled study. Primarily, safety was evaluated. The hemoglobin count (HC) and serum creatine kinase (CK) levels of the patients in the locked (n = 47) and unlocked (n = 35) groups were measured just before and 24 hours after operation. Hemoglobin deficit, increase in CK and the additional hemostatic sutures were compared. Secondly, uterine scar healing was evaluated three months later. Scar thickness, niche and percentage of thinning of the scar region of the locked (n = 27) and unlocked (n = 32) groups were calculated and compared. RESULTS The hemoglobin deficit was similar in two groups. CK rise was less in the unlocked group but it was not significant (P = 0.082). Unlocked group needed more additional sutures (P = 0.016). The thickness of the niche and the percentage of thinning of the scar region were significantly less in the unlocked group (P= 0.002, P=0.000). CONCLUSIONS Unlocked uterine closure technique is safe and has less damage to the myometrium.