Taurine is the amino acid with the highest concentration in the human body. Its physiologic functions are not yet well understood. As a neurotransmitter or neuromodulator it may display inhibitory functions. We have measured taurine levels in plasma and cerebrospinal fluid of migraine patients during attacks, comparing them with controls. Patients with migraine had significantly higher concentrations than controls. No sex or age influence over the amino acid levels were observed. Plasma taurine levels in patients with classic migraine correlated negatively with severity of headache. Central taurine liberation during migraine crisis may be due to spontaneous depolarization or a defensive reaction in the context of cerebral homeostatic processes.