One of the difficulties facing schizophrenia patients is a failure to construct appropriate relationships with others in social situations. This impairment of social cognition is also found in autism-spectrum disorder (ASD). Considering such commonality between the two disorders, in this study we adopted the Autism-Spectrum Quotient (AQ) score to assess autistic traits, and explored the association between such traits and gray matter (GM) alterations of the brain in schizophrenia. Twenty schizophrenia patients and 25 healthy controls underwent structural magnetic resonance imaging (MRI), and AQ was assessed, comprising five subscales measuring different facets of autistic traits. Voxel-based morphometry (VBM) was applied to investigate the correlation between these AQ scores and regional GM alterations. Schizophrenia patients showed significantly higher scores in total AQ, and in four of the five subscales, compared to healthy controls. The total AQ score in schizophrenia showed significant negative correlation with GM volume reduction in the cortical area surrounding the left superior temporal sulcus (STS), which is considered to be important in social perception. Our findings suggest a possible neuroanatomical basis of autistic tendencies in schizophrenia.