This study was performed on 30 female and 18 male mongrel cats, of which 36 appeared to be right- and 12 left-pawed, respectively. The physical features of the brain hemispheres and the paw preferences in cats were investigated related to both functional and morphological asymmetry. Right-pawed cats were more prevalent, with scores ranging from + 60 to + 80%, as compared with the left-pawed ones scoring from -40 to -60%. However, females were found to be more right- pawed than males, but the differences were not considered significant (p >.05). After half-open ether anesthesia, the whole brain was excised by craniotomy under deep-anesthesia (Ketalar(R): 40-50 mg/kg). The brains excised were kept in formaldehyde (10%) for three days, and then the weight, volume, density, and the morphological dimensions of left and right hemispheres and whole brain bodies were measured. There were no significant sex-related differences in body weights and paw preferences; nor was there any relation among the weights, volumes, and lengths of right and left hemispheres in either sex. There was, however, a significant sex-related difference between the mean heights of the left hemispheres of both male and female cats (p <.05), which is expected to be on the right hemispheres. As for the total samples, the mean density of the left hemispheres exceeded that of the right hemispheres.