OBJECTS: Many studies have demonstrated greater frequency of soft neurologic signs in patients with schizophrenia than in controls. However, factors associated with chronicity, institutionalization, individual differences and neuroleptic medication make it difficult to interpret these results. We report on our ongoing study of soft neurologic signs and their relationship to neuroleptics and institutionalization in schizophrenia. METHODS: Soft neurologic signs were examined with a standardized instrument, Neurological Evaluation Scale- Korean Version(NES-K) in 11 neuroleptic-naive patients with schizophrenia, 17 neuroleptic-treated patients and 14 chronically institutionalized patients. RESULTS: Scores of total items(p<0.005), sensory integration(p<0.05), sequencing of complex motor acts(p<0.05) and others(p<0.01) functional areas of NES-K were significantly different among three groups. There was no difference in the area of motor coordination. Posthoc analysis showed that scores of total items(p<0.005) and sensory integration areas(p<0.01) of NES-K were significantly higher in the institutionalized patients than those of neuroleptic-naive group. However scores of sequencing of complex motor act and others categories were not different in the institutionalized and neuroleptic-naive patients. CONCLUSION: These findings suggested that neuroleptic treatment or chronic institutionalization might partially affect soft neurologic signs, especially sensory integration area, in patients with schizophrenia. However, the soft neurologic signs of motor coordination area could be a biological trait marker of schizophrenia independent of confounding variables.