Both genetic and nongenetic risk factors for schizophrenia have been described. Specifically, perinatal complications have been suggested as a factor in the later development of schizophrenia. These appear to be increased among schizophrenic patients with a clear genetic vulnerability for illness. While reduced brain tissue localized to the temporal lobe is also present in these individuals, it is unknown whether brain structural differences are a consequence of perinatal insults to the developing brain. Initial analyses on magnetic resonance imaging scans from siblings with schizophrenia are presented in an attempt to examine this issue.