Taurine is the amino acid with the highest concentration in the human body. Its physiologic functions arenot yet well understood. As a neurotransmitter or neuromodulator it may display inhibitory functions. We havemeasured taurine levels in plasma and cerebrospinal fluid of migraine patients during attacks, comparing themwith controls. Patients with migraine had significantly higher concentrations than controls. No sex or ageinfluence over the amino acid levels were observed. Plasma taurine levels in patients with classic migrainecorrelated negatively with severity of headache. Central taurine liberation during migraine crisis may be due tospontaneous depolarization or a defensive reaction in the context of cerebral homeostatic processes.