Long-term results after septoplasty are not satisfactory. Apart from a recurrence of deviation, there are various reasons for this: false preoperative analysis, complete straightening of the septum, and a disturbed nasal cycle. Preoperative functional diagnostics with a combination of rhinoresistometry, acoustic rhinometry, and long-term rhinoflowmetry are necessary for differentiating between "physiological" and "pathological" septal deviations and recognizing other causes for obstruction. The surgical procedure of septoplasty includes approach, mobilization, resection, reposition, and finally reconstruction of all three layers. The goal of the operation should not be complete straightening of the nasal septum. The space between the septum and turbinates is of utmost importance. It should not be enlarged as much as possible; rather, it must be shaped in such a way as to allow freely congestion and decongestion reciprocal on the two sides during the nasal cycle.