To determine whether there are metabolite changes in the left medial temporal and frontal lobes with aging, we performed proton magnetic resonance spectroscopy in 36 normal subjects. The N-acetylaspartate/creatine-phosphocreatine ratio in the medial temporal lobe tended to be decreased in subjects over 60 years of age. The ratio decrease in the frontal lobe related to aging was lower than that in the medial temporal lobe. There were no significant differences in the metabolite ratios between males and females. These findings suggest that structures in the medial temporal lobe may be more susceptible to neuronal dysfunction associated with aging than those in the frontal lobe.