The author believes that the use of humor by the psychiatrist is potentially destructive to the psychotherapeutic relationship. Sometimes experienced therapists can use humor without doing harm, but beginning therapists who imitate them may do irremediable damage. Too often the patient's stream of feeling and thought is diverted from spontaneous channels by the therapist's humor; it may even be arrested and blocked. While humor has its place in life, psychiatrists should acknowledge that it has a very limited role in psychotherapy.Abstract Teaser