• We examined the relationship between computed tomographic (CT) scan hemispheric asymmetries and postmortem brain asymmetries of the planum pemporale region in the same 15 subjects (right-handed men). A significant correlation was found between occipital length asymmetry visible on the CT scan slice at the level of the bodies of the lateral ventricles and planum temporale length asymmetry found at autopsy. We believe that some CT scan asymmetries may be indexes of underlying anatomic brain asymmetries. These anatomic brain asymmetries, in turn, may underlie some functional asymmetries observed in humans, especially those asymmetries related to language.