The discovery of the Cone Beam computed tomography and its introduction into the practice of dental medicine, significantly facilitated and accelerated the daily work of dentists as well as reduced the number of errors made during work. The three-dimensional examination of teeth and surrounding anatomical structures enabled the planning of endodontic procedures, made them safer and reduced the chances of postoperative complications. Three-dimensional diagnostics in endodontics has found its application in the presentation of periapical processes, root canal morphological variations, root fracture diagnosis, maxillary sinusitis and traumas. Despite numerous positive aspects of CBCT diagnostics, such as highdetail resolution, the possibility of adjusting the contrast and a relatively short exposure time, the use of this imaging method has negative aspects as well. One of them is patient radiation exposure, which is still greater than while using two-dimensional (2D) imaging. Therefore, before using CBCT diagnostics, the ALARA (as low as reasonably achievable) principle which favours conventional radiography should be taken into account. The aim of this paper is to describe the use of CBCT in endodontics, the main indications for its use and their positive as well as negative aspects.