This case report describes the three-dimensional (3D) endodontic treatment planning of a complex mandibular incisor using the 3D Endo software (Dentsply Sirona, Bensheim, Germany). Apart from a step-by-step description of the planning, the actual endodontic treatment is shown, and possible indications for the 3D Endo software are discussed. Keywords: cone beam computed tomography, CBCT, endodontics, 3D Endo