Cluster headache (CH) is among the most painful headache disorders. There is still no unifying pathophysiological hypothesis to explain the trigeminal distribution, the circadian periodicity and the autonomic symptoms of the syndrome. We report the case of a patient with worsening of CH following administration of pramipexole for a restless legs syndrome (RLS). This observation supports the hypothesis that the dopaminergic system may play a role in the genesis or trigger of CH.