This study deals with the controlling of dangerous, assaultive behavior in an organically damaged, moderately retarded adult. The major therapeutic tool was a faradic stimulator employed in a punishment behavior modification paradigm. Baseline and experimental treatment periods of the study are described with emphasis on building in professional consent, positive reinforcements, and controls for counteraggression. The results were startlingly positive in terms of lowered frequency but somewhat disappointing in terms of desired outcome. The use of punishment in general is discussed with regard to this case. It is the general opinion of the paper that appropriately safeguarded punishment therapy should be raised on the preferred hierarchy of treatments for this type of problem.