Migraine comprises a great many encephalic structures in its pathophysiology with the trigeminal nerve (TN) type being one of the main ones. For the purpose of determining a possible influence of the greater occipital nerve (GON) on migraine behavior, 37 patients who showed this pathology were studied. Using a double blind "cross over" group and submitting those patients to a GON infiltration with bupivacaina 0.5% (BP) and physiological serum 0.9% (PS), the clinical effects were evaluated: subjectively, through a pain analytical visual scale; objectively, by determining the threshold of pain perception (algometry). The comparison between the two groups (BP-PS) and (PS-BP) has shown that the number and duration of the attacks did not show significant statistical differences during the study. The intensity of the attacks was lower in group (BP-PS) only after the second infiltration (p=0.020), in the other moments no differences have been observed between the groups. The conclusion is that the anesthetic blockage with BP on the GON does not change the number of crises and their duration, but it does provokes an intensity reduction after 60 days from the infiltration. The results shown here suggest that GON participates in the cranial nociceptive modulation during crises of migraine without aura.