Expanded endonasal approaches (EEA) for the treatment of skull base tumors are rapidly evolving. Good exposure, a complete resection, and the subsequent reconstruction of the resultant defect are paramount requirements for an optimum outcome. In some cases, partial or complete septal resection needs to be carried out to achieve an adequate approach or to reconstruct the skull base defect. Subsequently, septal perforation and aesthetic changes may occur in some cases. Other causes of septal perforations include trauma, complications after rhinoplasty and endonasal sinus surgery, inflammation or infection, neoplasms, or abuse of inhaled substances (e.g., cocaine). This atlas offers a complete review of all endoscopic approaches that are available for the repair of the nasal septum. Each approach is described step-by-step in series of pictures from fresh cadaver dissections.