This guide to preventing self-injurious behavior, in question-and-answer format, is intended for parents, teachers, and other caregivers of people with disabilities. It describes the more common types of self-injurious behavior, discusses methods for identifying causes of self injury, and outlines interventions. Specifically, the guide covers: (1) characteristics of self injury, including a definition, incidence data, and particular disabilities often associated with self injury (i.e., autism, Cornelia de Lange syndrome, Fragile X syndrome); (2) causes of self injury, focusing on current beliefs that self-injurious behavior usually has multiple causes, the role of medical problems, the possible role of dietary factors, self injury as a form of communication, and the relationship of self stimulation to self injury; and (3) treatments for self-injury, such as drug treatment, communication training, providing a positive environment with more rewarding activities than self injury, and response suppression procedures. Eleven additional sources of more information are listed. (DB)