This article uses Scott's definition of dangerousness as 'an unpredictable and untreatable tendency to inflict or risk irreversible injury or destruction or to induce others to do so.' The knowledge base essential for social workers who deal with such offenders includes clinical psychiatry, modes of psychotherapy, psychology, the sociology of institutions, politics, social policy, law, ethics, and basic psycho- and neuro-physiology. In terms of skills, the general social work skills of listening, advising, mediating, and advocating are applicable. Particularly important is the ability to identify clues and cues about actual or potential behavior. The counselor should be particularly sensitive to the 'hidden meanings' of behavior. Although there are no fool-proof actuarial devices for predicting dangerousness, the counselor can make some assessment of dangerousness by (1) examining the nature of any past precipitating stress factors in the offender's social environment, (2) assessing the offender's capacity for sympathetic identification with others, (3) determining if the offender derives satisfaction from inflicting pain on others, (4) examining previous employment, and (5) considering how the offender talks about his offense and behavior. Some essential attributes for the counselor in dealing with dangerous offenders are to acknowledge one's own potential for violence, be able to control panic reactions, have a capacity to adopt a comprehensive view of a person, have the courage to undertake direct intervention, have the capacity to respond rapidly in crisis situations, and the ability to guide persons in the discussion of their feelings. Forty-seven footnotes are provided.