In our “politically correct” society any consideration of sex differences is often approached with trepidation. In neuroscience they have been frequently underemphasized and altogether ignored. Indeed, the perusal of any neuroanatomy text will leave one with the impression that human brain is perfectly androgynous, since no mention of sex differences likely to be found. But female and male brains are characterized by subtle morphological and functional differences. The differences are indeed subtle, so we are not talking about two different themes but rather about two variations on the same theme. Several among the subtle differences in question involve cerebral hemispheres. Both structurally and functionally, the hemispheres are more symmetric in females and more asymmetric in males. The exact nature and degree of these asymmetries are still being studied, but it is obvious that the more precisely we understand these differences the better we will be able to customize our diagnosis and particularly the rehabilitation of a wide range of neurological disorders.