BACKGROUND Migraine and hypertension are common conditions that frequently coexist. The relastionship between the two is usually coincidental, but some evidence suggests that poor control of blood pressure may exacerbate the frequency and severity of migraine. OBJECTIVE To review the relationship between migraine, other headaches and blood pressure and to discuss guidelines for suitable therapy for both conditions when they occur together. DISCUSSION Establishing the blood pressure should be a routine task in the assessment of all headache patients. Severe hypertension in the setting of new acute headache may indicate a serious underlying cause and requires urgent investigation. In patients with migraine and established hypertension, good control of blood pressure may be beneficial in controlling their headache. Many of the drugs used to treat hypertension may cause headache and some agents used to treat migraine can exacerbate hypertension and so careful consideration of the therapeutic options is important.