Changes in sulcal cerebrospinal fluid (CSF) volume have been related to the neurodegeneration hypothesis in schizophrenia. Fifty-three (24 neuroleptic-naive) schizophrenics and a control group (n=26) were studied with MRI to assess regional sulcal CSF values relative to the total volume of brain lobes (prefrontal, orbital, temporal, parietal, and occipital). Segmentation of brain structures was performed using an automatic Talairach-based method. Relative CSF volumes were adjusted for age by means of linear regression from normal subjects; the corrected values were used to assess their relationship with illness duration and age of onset (AOS). The volume of sulcal CSF on prefrontal and temporal lobes (bilateral) was significantly greater in schizophrenic patients and showed a significant positive correlation with illness duration not found in the other regions studied. No significant association between CSF volumes and AOS was found in any region. Our findings support the existence of a degenerative process in schizophrenia located in prefrontal and temporal areas.