The five basic types of mistreatment of the elderly are passive neglect, psychological abuse, material or financial abuse, active neglect, and physical abuse. Although definitive data regarding the extent of mistreatment do not exist, it is clear that passive neglect is the most widespread form. Different types of mistreatment are probably caused by different combinations of the personal traits of the people involved, household finances, the interpersonal relationships that have developed over time, external events affecting the household, and similar factors. Middle-income families that cannot afford outside help appear to suffer the greatest stress and fatigue in caregiving situations. Most jurisdictions have protective services laws providing for intervention, advocacy, and mandatory reporting of suspected abuse or neglect. However, prevention should be the focus. Primary prevention efforts based on education can reduce the probability of mistreatment. Secondary prevention, which consists of preventing further mistreatment, is also needed. It includes casefinding activities, counseling, training, personal assistance, respite for caregivers, and crisis intervention. To protect themselves, elderly persons should decide while they are healthy who is to care for them and manage their affairs if they become physically or mentally incapacitated. A variety of legal processes exist to handle decisions regarding incapacitated persons. Recommended guidelines and action steps for elderly persons, for family members, and for communities; list of services that may be needed; glossary; and 14 references.