A survey of 14 published studies found no consistent association between specific HLA antigens and schizophrenia. Since these studies lacked diagnostic or biological criteria, an investigation was undertaken using recognized diagnostic criteria and CT scan findings. Typing for HLA antigens at loci A, B and C was carried out on 130 patients. Among 92 black schizophrenic patients there was an increase of HLA-A2 which remained significant even after correcting for the number of antigens studied. When the patients for whom CT scans were available were divided according to the presence or absence of evidence of brain atrophy, there was an increase of A2 in the black schizophrenic patients without evidence of atrophy, which remained significant after multiplying by the number of antigens studied. However, there was no significant increase of A2 in those with evidence of atrophy. Similar trends held for the white population but they failed to reach significance. The need for HLA studies on biologically defined groups of schizophrenic patients is stressed.