(Geriatr Nurs 2009;30:174-187) Aggressive behavior of residents continues to challenge and burden caregivers working in nursing homes [1,2]. Working in a nursing home or long-term care facility is associated with a high risk of experiencing aggression [3].Studies show that aggressive behavior is more likely to occur among older people with cognitive impairment than among those with no cognitive impairment [2,4,5] although cognitively intact residents also threaten or assault the caregivers [6]. Irrespective of whether demented residents can be held responsible for their aggressive behavior, many gerontological nurses find that physical or verbal attacks by an elderly person they are giving nursing care to is one of the most difficult, emotionally distressing, and potentially dangerous aspects of their work [7], often resulting in feelings of powerlessness, sadness, anger, and ineffectiveness [8].Some studies have investigated the prevalence of aggression and associated factors in nursing homes, but it is probable that nursing home residents' aggressive behavior often goes underreported in both prevalence measures and nursing documentation. Possible causes for underreporting are a lack of competence to cope with aggressive behavior, feelings of failure, or the assumption that aggressive behavior is a common feature in the care of the elderly, especially those with psychological disturbance [1,4,9,10]. Psychological disturbances and other illnesses in the elderly may lead to aggressive behavior irrespective of situational factors. However, because such illness processes can be influenced only indirectly by nursing