Helping professionals such as social workers, nurses, doctors, and prison staff sometimes work with people who are undergoing considerable trauma. Therefore, professionals need to learn to cope with aggression and to realize that their attitudes and assumptions are important in dealing with potentially violent situations. Case examples from violence prevention seminars suggest that many violent incidents might have been avoided or reduced in severity if certain precautions had been taken. Such precautions do not depend entirely on efficient facility design or on liaison among professionals; they also depend on the individual's personal style and skills in the work setting. Precautions are necessary to protect helping professionals in the institutional setting and in the course of home visits. Appropriate communication and nonverbal behavior with an aggressive or agitated individual is important in violent incident management. Sometimes, it is appropriate to remain calm, while other situations require the helping professional to match the aggressor's level of arousal. 19 references, 3 figures.