Although cartilaginous incisions are effective in straightening the deviation of the cartilaginous septum, the resultant morbidity is seldom addressed. We examined 1,164 patients who underwent septoplasty by the senior author. The patients were randomly subjected either to septal reconstruction by conventional cartilaginous incisions or to our modification of cartilaginous incisions. During the follow-up of 11 months to 7 years with an average of 2.5 years, saddle deformity of the external nose was observed in 10 of 567 patients (1.8%) who underwent septal reconstruction by conventional septal incisions, while no saddle nose deformity was observed in patients who underwent septal reconstruction by our modification of septal cartilaginous incision. Inattention to cartilaginous weakening from incisions may expose the patient to an unnecessary risk of complications. Nasal resistance on the narrow side of the nose was significantly decreased after septal reconstruction using the two techniques of cartilaginous incision. The results of this study suggest that our modification of cartilaginous incision may be an efficient, safe technique to decrease nasal resistance and to prevent saddle nose deformity of the external nose after septal surgery.