Objective We describe our experience for repair septal perforation with a septal flap and we analyse the route of the septal branch of the anterior ethmoidal artery (AEA) in the septum area with a radiological anatomy study in order to perform this flap. Study design We carry out a prospective analysis with computed tomography scan in the cadaver heads and we perform an endoscopic technique in the patients. Methods Ten nasal cavities were analysed in five adult cadaveric heads and two patients diagnosed with anterior septal perforation were surgically treated. Measurements in the cadaveric heads were obtained from a sagittal plane of the nasal septum. The anterior point corresponds to the projection of the anterior insertion of the middle turbinate in the frontal process of the maxilla over the nasal septum. The posterior point was obtained with a vertical line passing through the entrance of the AEA in the nasal septum. Results The mean distance between the anterior point and the posterior point was 7.35 mm with a standard deviation of 0.95 mm. The lowest value was 5.5 mm and the highest value was 8.7 mm. We observed good epithelialisation and closure of the perforation in all patients. Conclusion The unilateral septal flap pedicle by anterior ethmoidal artery may be used for small and medium perforations with a pedicle smaller than 1 cm posterior to the axilla.