The authors studied auditory brainstem evoked potentials (BAEP) in 27 organ donors aged 40 to 68 years treated in neurosurgery units in Szczecin and Grenoble. Abnormal results were found in all cases. In 63% of cases no evoked action potentials were obtained, in 34% only the 1st wave was obtained, and in two cases evolution was observed with activity extinction. The authors believe that in the process of shaping of BAEP morphotic extinction begins from the later waves to earlier ones in agreement with the rostrocaudal direction of extinction of the functions or brain midline structures, and in a single study various findings may be obtained.