A prospective study of 46 patients with mixed connective tissue disease (MCTD) revealed that 16 (35%) had recurrent, vascular headaches. Detailed neurologic evaluation of 12 headache patients available for further study revealed the following: 3 had lateralized, throbbing headaches; 9 had bilateral headaches; 8 patients experienced prodromal symptoms (7 had visual auras); and 3 experienced nausea or vomiting. Only 1 patient described headache as interfering with daily activities, and no patients were prostrated. Only 1 patient had frequently required narcotic (codeine) therapy, and none were employing ergot. Headache symptoms have persisted in 8 patients; 5 of these 8 suffer at least 1 headache per week. It appears that frequent vascular headache of mild to moderate severity is a relatively common symptom in MCTD.