The posterior superior temporal gyrus (STG) is the approximate site of Wernicke's area, a language region, which in previous studies has been reported to be abnormal in adults with schizophrenia. The present study assesses volumetric differences in the superior temporal gyrus of subjects with childhood-onset schizophrenia (COS). MRI scans of 18 subjects diagnosed with childhood-onset schizophrenia and 16 age- and sex-matched normals were analyzed to assess possible volume differences. The COS subjects displayed significant enlargement of the right posterior superior temporal gyrus, showing white matter increases bilaterally in this region. Our findings are consistent with studies that have found increased volumes in temporal lobe regions in COS and may provide a possible neural correlate for the language impairment observed in COS patients.