The purpose of this study was to determine the correlation between the expression patterns of heat shock proteins (HSP) and Fos proteins in the central auditory pathways after acoustic stimulation. Sprague-Dawley rats were exposed to 4KHz pure tone with 90, 100 and 110 dB SPL and sacrificed at 1, 3, 6, 9 and 12 hours after stimulation. Auditory brainstems were obtained and sectioned with vibratoma for immunohistochemistry. Immunoperoxidase immunohistochemistry was carried out to detect the expression of HSP and c-fos using monoclonal anti-HSP 72 antibody (StressCen) and polyclonal anti c-fos antibody (Cambridge Biochemical). HSP 72 immunoreactive staining was seen in cochlear nucleus, lateral superior olive and medial nucleus of Trapezoid body at the intensity of 110 dB SPL, while lower intensity acoustic stimulation did not induced HSP 72 expression. Maximal immunostaining was obtained at 6 hours after stimulation. Fos-like immunoreactive staining was seen in cochlear nucleus, medial nucleus of Trapezoid body and inferior colliculus at 1 hour after stimulation of any intensity and their expression level decreased at 3 hours and disappeared after 6 hours. These results suggest that HSP 72 and c-fos were induced with same acoustic stimuli (same frequency and intensity) and c-fos expression may be an early component of transcription activation in auditory neurons which can induce HSP 72.