Thirty-two female (mean age = 52.9 years [SD = 9.2]) patients with a diagnosis of residual schizophrenia and 19 female (mean age = 51.1 years [SD = 12.7]) control subjects were studied through cerebral Magnetic Resonance Imaging. Along the entire surface of the septum pellucidum, 1-mm coronal slices were performed in all subjects. The authors classified the cavum septum pellucidum into three types based on embryological development. The prevalence of a cavum was significantly higher in the patients with schizophrenza (Chi square 6.112. p < 0.05). No other significant associations with previously described morphological brain changes were found. Although this result was found in previous reports (DeGreef et al., 1992; DeLisi et al., 1993), our discussion focused on the neurodevelopmental theory of the septum pellucidum and its possible association with schizophrenia.