The aim of this systematic review was to evaluate how treatment plans changed when cone beam computed tomography (CBCT) imaging was used in endodontic treatment decision-making. Studies examining changes in clinicians' treatment plans with and without the use of CBCT were included. Risk of bias assessment was completed using a modification of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. A systematic search was performed in PubMed, Embase, Scopus, Cochrane databases from inception to 14 September 2021. The initial search identified 3379 titles and abstracts; 20 articles fulfilled inclusion and exclusion criteria for full text review. An additional three articles were identified through citation searching. Sixteen studies met inclusion and exclusion criteria for data extraction and analysis. Fifteen studies reported changes in treatment plan with CBCT imaging. Five studies reported changes in 45 - 66.7% of the cases but did not mention specific treatment options. Of the 11 remaining studies, 10 studies reported changes in 24.3 - 56% of cases and changes in treatment options, while one study reported no significant change in treatment plan after CBCT imaging was introduced. With CBCT imaging, clinicians were more likely to prescribe further intervention that included endodontic treatment and extractions. Although the current evidence was heterogeneous, it was clear that CBCT offered more information than periapical radiography. This influenced endodontic treatment decision-making and in more complex cases, led to further intervention including non-surgical and surgical endodontic treatment and extractions. Additional information from CBCT imaging influenced endodontic treatment decision-making in the following situations: high difficulty cases, diagnosis of symptomatic teeth after failed root canal treatment, evaluation of periapical healing, pre-surgical treatment planning, and management of traumatised immature teeth and external cervical resorption.