MRI is an important research tool which enables to investigate the brains of neuropsychiatric patients in vivo. In our study we tried to measure the volumes of some limbic system structures in the normal population to be utilized for further MRI morphometric studies in neuropsychiatry. We measured the volumes of hippocampus and corpus amygdaloideum (amygdaloid body), and the widths (thickness) of fornix and corpus mammillare (mammillary body) in 42 healthy volunteers without any neuropsychiatric pathology. The 1.5 T MRI was taken at oblique coronal plane using a section thickness of 3 mm without any gap. The volumes of hippocampus and corpus amygdaloideum were normalized according to intracranial area. We also investigated right-left volume differences for hippocampus and corpus amygdaloideum and set a formula as % difference rate for fornix and corpus mammillare width. We found the right hippocampus and corpus amygdaloideum larger than the left. No sex effect were evaluated. In addition, the larger hippocampus did not mean larger fornix. As a conclusion, the MRI morphometric data for normal population and the relations of this data with certain parameters such as side, sex, age must be collected to assess the pathological values in MRI morphometry. © neuroanatomy.org.