Introduction: Vertical root fracture (VRF) is a root-canal treatment complication and is a major reason for extraction of the root-canal-treated teeth. The diagnosis of VRF can be complicated because of absence of specific signs, symptoms, and radiographic features. A combination that includes the presence of deep pocket and a sinus tract in root-canal-treated tooth was proposed as a pathognomonic for VRF. The purpose of this study was to systematically search and evaluate the literature regarding the correlation between the clinical signs considered pathognomonic for the diagnosis of VRF, with the actual reference standard by means of systematic review of the literature. Methods: A systematic search of the literature was performed to identify studies evaluating the clinical signs considered pathognomonic for the diagnosis of VRF. The following databases were searched: Medline (PubMed), Scopus, and Cochrane Central. The identified studies were subjected to strict inclusion and exclusion criteria. Results: Initially, 1141 possible relevant articles were identified. After title and abstract screening, 40 articles were subjected to a full-text evaluation, 3 articles met the inclusion criteria and contained data regarding the prevalence of the pathognomonic combination in VRF’s-confirmed teeth. The presence of deep pocket and a sinus tract in endodontically treated teeth was found in 28% of the cases. Conclusion: To date, the current scientific knowledge regarding the correlation between the clinical symptoms considered pathognomonic for VRF diagnosis in the root-canal-treated tooth and the actual reference standard is quite low.