40 patients were evaluated for skin temperature changes from baseline measurements and after 6 mg subcutaneous sumatriptan administration. During examination, skin temperature were recorded on a color picture at 10', 20', 30', 60', 90' and 120 minutes after sumatriptan administration. At the some time, heart rate (HR), systolic (SBP), diastolic (BDP) blood pressure and ECG-monitoring were automatically recorded. The patients were subgrouped as follow: 20 non migrainous control subjects (6 males and 14 females) aged 19 to 55 years (mean age 39.5 +/- 15.4); 20 headache free migrainous patients (6 males and 14 females) aged 25 to 46 years (mean age 37.8 +/- 8.4). Our data demonstrate a significant reduction in skin temperature (face) in all patients studied. 10 minutes after sumatriptan administration a significant increase (p > 0.001) both in SBP and BDP was observed. This findings suggest that sumatriptan show a vasoconstrictor effect as demonstrate by reduction in face temperature both in nonmigrainous and in migrainous patients. The unchange in HR and ECG and the transient increase in blood pressure, not associated with clinical symptoms, suggest that this drug may be used in migrainous patients.