We report three patients with transformed migraine, previously refractory to a wide variety of traditional preventive pharmacologic and nonpharmacologic interventions. Naratriptan 2.5 mg given each morning, with a second tablet allowed for breakthrough headache, at least 4 hours later, demonstrated a remarkable reduction in frequency and intensity of daily headache. In addition, a subjective improvement in quality of life and restoration of functioning including a decrease in missed workdays was noted. All three patients had previously experienced good responses to sumatriptan or zolmitriptan, but were limited in frequency of use by the authors. The patients were not experiencing rebound phenomena at the onset of treatment with naratriptan. Clinical responses were noted within 3 to 7 days of initiation of treatment. Traditional risk factor analysis and screening were performed. Naratriptan was extremely well tolerated, with no cardiovascular adverse events reported or observed. Possible mechanisms of action are discussed.