The high frequency components of an auditory stimulus are considered to be the primary contribution to median plane localization. However, a number of studies have demonstrated that the low frequency components of a stimulus are also important in median plane localization. Asano et al. concluded that important cues for front-back discrimination seem to exist in the frequency range below 2 kHz. In the present paper, localization tests were performed in order to examine the contribution of low frequency components to median plane localization. In these tests, the higher (above 4,800 Hz) and lower (below 4,800 Hz) frequency components, respectively, of a wide-band white noise were simultaneously presented from different directions so that the individual components provided different directional information. The results of these tests reveal that: (1) when the source is a wide-band signal, the higher frequency components are dominant in median plane localization, whereas the lower frequency components do not contribute significantly to the localization, and (2) important cues for front-back discrimination do not exist in the low frequency range.