Among the primary headaches, patients with migraine are those that seek for medical help the most. Its prevalence is estimated in 12% of the population being more common in women with a prevalence of 18 to 20%, 6% of the men and 4 to 8% of the children. Its economic impact in the productivity and leisure is significant, and the headache attacks may incapacitate the patients for the usual activities. With a complex and still unknown pathophysiology, migraine may present with intermittent and peculiar episodes of intense headache. The most efficient approach for the treatment includes the avoidance of the trigger factors, preventive treatment, rescue treatment for the moments of pain and the accessory or non drug treatment. For the preventive treatment, scope of this update, various classes of substances are used and include the beta blockers, tricyclic antidepressants (and recently the selective serotonin reuptake inhibitors), calcium antagonists, serotonin antagonists, anticonvulsants and others. Even though its mechanisms of action in the treatment of migraine are unknown, it seems that all of the drugs influence the central serotonergic, noradrenergic and gabaergic functions. New proposals for the mechanisms of action of some of these drugs, also include the inhibition of the synthesis of nitric oxide and the modulation of the neuronal cationic channels. When individualized and correctly used, these preventive medications have been held responsible for important reductions in the frequency and intensity of migraine episodes, decreasing this way, the marathon of suffering and doubtful approaches, that these patients are usually submitted.