Children with 22q11.2 microdeletions (Velocardiofacial Syndrome; VCFS) have previously been shown to exhibit learning deficits and elevated rates of psychopathology. The aim of this study was to assess regional brain abnormalities in children with 22q11DS, and to determine the relationship of these measures to neurocognitive and behavioral function. Thirteen children with confirmed deletions and 9 demographically matched comparison subjects were assessed with a neurocognitive battery, behavioral measures, and high-resolution MRI. Twenty-two qllDS children showed a nonsignificant 4.3% global decrease in total brain volume as compared to healthy controls,with differential reduction in white matter, and significantly increased sulcal cerebrospinal fluid (CSF) in temporal and posterior brain regions. In 22q11 DS subjects, but not controls, bilateral temporal gray and white matter volumes were significant predictors of overall cognitive performance. Further, reduced temporal gray matter was associated with elevated Thought Problems score on the CBCL. Results indicate that global alterations in brain volume are common in children with 22q deletions, particularly those with low IQ and/or behavioral disturbance. Although preliminary,these findings suggest a possible underlying pathophysiology of the cognitive deficits seen in this syndrome,and provide insight into complex gene-brain-behavior relationships.