Root fractures are not a common injury, but a thorough understanding of their etiology, healing responses, diagnosis, management, and prognosis is essential. The prognosis is largely related to the patient's age; degree of displacement, if any, of the coronal fragment; and the location and orientation of the fracture. The more apical the fracture is located, the better the prognosis. Teeth with root fractures located supracrestally may have the worst prognosis, but their management and outcome depend on many factors, with the most influential factor being the ability to restore the tooth because the coronal fragment usually needs to be removed. In contrast, root fractures located in the apical and middle thirds and those subcrestally in the coronal third of the root have a good prognosis and usually require little, if any, treatment apart from immediate repositioning (if the coronal fragment has been displaced) and stabilization. Monitoring of root-fractured teeth over time is essential to determine the healing response and to assess whether the pulp survives or not. In some cases, the pulp in the coronal fragment may necrose and become infected, thus requiring root canal treatment, but this should only be done to the fracture line. Pulp necrosis and infection typically occur within the first 3-4 months if it is a direct result of the trauma. However, pulp necrosis and infection can also occur many years later, in which case it is likely to be a result of bacterial penetration via cracks or breakdown of restorations. Overall, root fractures should be managed conservatively unless they are located supracrestally. © 2019 John Wiley & Sons A/S and American Association of Endodontists.