Existing nomenclatures of septal deviation deal with the deformation of the nasal septum exclusively and are rarely used in daily clinical work. The aim of this study was to develop a classification of septal deviations based upon the anatomical structures of the nasal septum and common clinical concepts.We included patients undergoing septoplasty alone or in combination with rhinoplasty or functional endonasal sinus surgery by reason of septal deviation. Immediately after surgery, the surgeon recorded intraoperative findings of the nasal septum and the nasal turbinates in a data sheet and a standardized drawing for every patient.Data from 1088 patients were analyzed. Six types of septal deviations were identified. This new classification of septal deviations was developed with special regard to clinical anatomical findings. Leading as well as concomitant pathological findings were assigned to the six types of septal deviation. The frequencies of occurrence of hyperplasia of the inferior turbinate and concha bullosa of the middle turbinate were specified.The systematic assessment of relevant structures may help to develop improved surgical strategies. Furthermore, the systematic teaching of young surgeons to perform septal surgery may be facilitated.