The relationship between Borna disease virus (BDV) infection and positive and negative syndromes in schizophrenia was investigated. By nested RT-PCR and Western blotting, BDV-specific RNA and anti-BDV antibodies were examined in blood from 67 schizophrenic patients (DSM-III-R) in Japan, and the psychometric properties of the Positive and Negative Syndrome Scale (PANSS) were analyzed. There were significant (p < 0.05) differences in the composite index denoting the positive minus negative difference indicating a dominant contribution by negative items, and the proportion of negative type (positive minus negative value below zero) patients, between patients positive and negative for anti-BDV p24 antibodies. It is possible that BDV infection with induction of BDV p24 antibodies may be associated with negative syndromes in schizophrenic patients.