OBJECTIVE: Enlargement of the lateral ventricles is among the most frequently reported macroscopic brain structural changes in schizophrenia, although variable in extent and localization. The authors investigated whether ventricular enlargement is related to regionally specific volume loss. METHOD: High-resolution magnetic resonance imaging scans from 39 patients with schizophrenia were analyzed with deformation-based morphometry, a voxel-wise whole brain morphometric technique. RESULTS: Significant negative correlations with the ventricle-brain ratio were found for voxels in the left and right thalamus and posterior putamen and in the left superior temporal gyrus and insula. CONCLUSIONS: Thalamic shrinkage, especially of medial nuclei and the adjacent striatum and insular cortex, appear to be important contributors to ventricular enlargement in schizophrenia.