The ciliary neurotrophic factor (CNTF) is a neurotrophic cytokine that plays a critical role in neurodevelopment. On the basis of neurodevelopmental hypothesis, the CNTF gene has been a candidate locus for schizophrenia. Several studies have investigated the association between the null mutation of the gene and schizophrenia, however, with inconsistent results. In the present study, we investigated the association in 222 Japanese patients with schizophrenia and 237 controls. The association between the mutation and personality traits was also studied, to investigate the effect of the mutation in participants from the general population. As a result, no association was observed between the mutation and schizophrenia nor personality traits, evaluated by using the Revised NEO Personality Inventory scores. The present study did not provide evidence for the association between the CNTF gene and schizophrenia or personality traits in the Japanese population.