In the present study, 24 nonmedicated patients with social anxiety disorder (SAD) were compared with 24 healthy control subjects to assess metabolite levels in the anterior cingulate, insula, caudate, and putamen using proton magnetic resonance spectroscopy. The ratio of N-acetylaspartate (NAA)/creatine (Cr) was significantly higher in patients with SAD than in healthy control subjects in the anterior cingulate and insula. NAA/Cr ratios in the insula correlated positively with the Liebowitz Social Anxiety Scale total scores in patients with SAD. Our results support the significance and biochemical involvement of the anterior cingulate and insula in the pathophysiology of SAD.