Recent studies have implicated dopamine and the basal ganglia circuits in the pathophysiology of social phobia. Twenty-two patients who met DSM-III-R criteria for social phobia and 22 age- and sex-matched control subjects underwent magnetic resonance imaging (MRI). MRI was performed with a 1.5 Tesla General Electric Signa System. No statistically significant difference was demonstrated between social phobia patients and normal control subjects in respect to total cerebral, caudate, putamen, and thalamic volumes. Although this study failed to demonstrate any specific cerebral structure abnormalities in patients with social phobia, it did reveal an age-related reduction in putamen volumes in patients with social phobia that was greater than that seen in controls. This age-related reduction in putamen volumes in patients with social phobia was not correlated with the severity of their illness.