Root fracture is a rarely seen traumatic injury in permanent dentition. It has a prevalence of 0.5-7 %. Tooth survival is significantly affected by the type of healing and the location of the root fracture. Additionally, the patient’s age, stage of root development, mobility and dislocation of the coronal fragment, and diastasis between fragments following this kind of injury are among the important factors. In this case presentation, the management with MTA plug and 6-year follow-up of a horizontal root fracture was reported. A literature update regarding the use of MTA in the management of horizontal root fractures was also added to discuss its merit.