There are a number of hypotheses concerning the pathogenesis of migraine, but they are frequently conflicting. In addition to the vascular hypothesis, clinical data are available that excitatory amino acids may play an important role in the development of the disease. In this study, free amino acid concentrations were measured by RP-HPLC in the saliva of 23 migraineurs without aura, 14 migraineurs with aura, and 20 healthy subjects. Significantly higher concentrations of glutamic acid, serine, glycine, arginine, and tyrosine were found in the saliva samples of both groups of migraineurs relative to the control group. It is suggested that amino acids causing hyperexcitability in the central nervous system may be linked to the pathogenesis of migraine.