The purpose of this study is to evaluate the usefulness of rapid palatal expansion in growing patients to eliminate the nasal pyramid stenosis as a cause of primary headache. Patients were invited to participate in the clinical study at the University of Milan, Department of Orthodontics. Forty-one growing patients of both genders suffering from primary neurovascular headaches and having transverse maxillary deficiency were studied before and after rapid palatal expansion. A clinical examination, postero-anterior radiography and rhinomanometry were performed. After rapid palatal expansion (RPE) therapy all patients showed a constant and important increase in the values relating to both skeletal and dental structures, a significant reduction in the mean nasal resistance, and a significant decrease or elimination of headache symptoms. This therapy provides a preventive alternative for surgical procedures, such as the neurovascular decompressive septo-ethmoidosphenoidectomy performed in adult patients.