This study investigated serum brain-derived neurotrophic factor (BDNF) protein levels in schizophrenia patients and healthy control subjects and schizophrenia patients with various clinical phenotypes. During a 1-year period, 126 schizophrenic patients and 96 healthy control subjects were recruited. Serum BDNF protein levels were measured using an ELISA Kit. Psychiatric diagnoses were made according to DSM-IV criteria. One-way analysis of variance (ANOVA) showed no significant differences in serum BDNF protein levels between schizophrenia and healthy normals. Additionally, no significant differences existed in BDNF levels between schizophrenia patients for the following variables: with/without a suicide attempt; antipsychotic drug use, family tendency and disease onset before and after 25 years old. However, patients with catatonic schizophrenia had lower serum BDNF protein levels than patients with paranoid or residual schizophrenia. These analytical results suggested that BDNF might play an important role in the clinical subtypes of schizophrenia, but it needed further investigation in future.