Migraine is a common, disabling disorder that often requires preventive treatment. The decision to treat migraine preventively generally is based on disability, problems with acute medicines, patient preference, risk of acute medication overuse, special circumstances, and concern that high migraine attack frequency may be a risk factor for chronic daily headache. Migraine and epilepsy are comorbid episodic central nervous system disorders that can have stereotyped symptoms with negative and positive phenomena. Controlled trials have demonstrated the efficacy of anticonvulsants in migraine prevention. Valproic acid, topiramate and, to a lesser extent, gabapentin, have demonstrated efficacy in randomized, placebo-controlled trials. Lamotrigine may be effective at controlling migraine aura, but has not demonstrated effectiveness at controlling migraine headache. Anticonvulsants are a useful option for the preventive treatment of migraine.