Introduction: The purpose of the current case is to give a detail description on an incidence of a traumatized upper left central incisor with symptomatic periapical periodontitis which was root treated. Descriptions: The apical portion of the tooth had a large apical lesion with external root resorption that end up with an open apex due to the loss of tooth cementum, dentine and adjacent hard tissue. The tooth was endodontically retreated, and the apical region was treated surgically with apical curettage and retrograde Mineral Trioxide Aggregate filling (MTA). Results: The affected tooth was considered successful both functionally and aesthetically during a 12-month follow-up. Conclusion: Apicoectomy and retrograde filling with MTA is a viable option in case of treating traumatized tooth with large peri-apical lesion and open apex