OBJECTIVE: In this study, the volume and neuronal number of the pulvinar thalamic nucleus in schizophrenia patients were measured. METHOD: The authors examined medial and lateral pulvinar nuclei bilaterally in 27 patients with schizophrenia and 28 normal comparison subjects. RESULTS: In the comparison subjects, the medial pulvinar was larger on the right. The right but not left pulvinar nuclei were smaller in the schizophrenia patients than in the comparison subjects. The number of neurons showed similar trends. CONCLUSIONS: These findings confirm low pulvinar volume in schizophrenia and show that it affects both medial and lateral nuclei. The lateralized findings may reflect pulvinar connections with asymmetrical neocortical regions and their asymmetrical involvement in schizophrenia.