Diffusion tensor imaging was performed in 105 volunteers free of central nervous system lesions.No differences were found in fractional anisotropy between the left and right cerebral peduncles among subjects (P > 0.05). The lower limit value of fractional anisotropy was 0.36, and the asymmetry ratio was 0.77. The area and lower limit value of the cerebral peduncles were 0.90 cm2and 0.83, respectively. These results will be useful in evaluating the diagnosis of Wallerian degeneration following cerebral infarction.