Patients with migraine headaches are commonly encountered by clinicians both in the clinic and in the emergency department. Migraines impose a significant financial burden on patients, caregivers, and society. Up to 49% of patients treated acutely for migraine headache will have a recurrence within 72 hours. Recurrence of migraines is dependent on a number of factors, including the choice of abortive agent, age, sex, and initial severity of the migraine. Dexamethasone has been proposed and studied as a medication that may decrease the frequency of such recurrences of migraine headaches in affected patients. Dexamethasone is a corticosteroid that has been proposed to prevent recurrence of migraines through its prevention of neurogenic infammation. Initial trials, with less-than-ideal methodology, showed large decreases in the number of patients experiencing recurrent migraines. Later randomized controlled trials revealed mixed results, with subsequent meta-analyses showing an overall benefit in the prevention of recurrence of migraines. These meta-analyses suggest that dexamethasone will prevent recurrence in about 10% of patients, although trials that used higher doses of dexamethasone and followed patients for $ 72 hours showed a larger benefit. Very few adverse events were reported in the randomized controlled trials following a single dose of dexamethasone. Given the benign side effect profile and wide tolerability to a single high dose of dexamethasone, it appears to be a safe and modestly effective addition to standard migraine abortive therapy for the prevention of migraine recurrence. Dexamethasone should not be used in patients with non-migraine headaches or contraindications to steroids. Further studies should help delineate if dexamethasone can be tailored to specific patient populations and hence enhance its therapeutic effectiveness. © Postgraduate Medicine.