Plasma levels of excitatory and inhibitory amino acid neurotransmitters were assayed in 20 male patients following alcohol withdrawal and in 20 normal controls. All patients filled out an 'Alcohol withdrawal symptom monitoring sheet', including more than 20 symptoms. The levels of excitatory amino acid were higher and the values of inhibitory amino acid lower in the patients than in the controls. The correlation between the level of excitatory amino acid and the rating of subjective discomfort was positive, and the correlation between the level of inhibitory amino acid and the level of subjective discomfort was negative.