The purpose of this study was to determine the effects of aging and gender on the volumes of total brain, brainstem, cerebellum and lateral ventricle of healthy Koreans by magnetic resonance imaging (MRI). Using three-dimensional MRI volumetry, we compared the volumes of various brain regions according to age and gender in 115 healthy Koreans. There were significant differences in the volumes of midbrain, cerebellum and lateral ventricle, whereas those of brainstem and medulla showed no differences between old-age group and young-age group. Men have larger volume of medulla than women. Age-related differences in the volumes of total brain and pons were significantly larger in men than women.