Behavioral medicine is a newly emerging field dating back to the early 1970s. In this short time, a great deal of controversy and confusion has arisen as to even the definition of the term. Similarly, there are now a variety of different operational applications of this concept in patient care, research, and health care system organizations. It is proposed that the title "behavioral medicine" be used in the most general way, consistent with the definition developed by the Institute of Medicine meeting in 1978. In it, behavioral medicine is a term designating a very large field and is not analogous to a profession, medical specialty, or discipline. This term denotes a body of psychologic and social knowledge and a set of techniques applied to research, prevention, and treatment of medical illness, including psychiatric illness. By this definition, behavioral medicine treatment techniques would include psychotherapy, hypnosis, relaxation, behavior therapy, behavior modification, biofeedback, and pharmacotherapy. One of the cardinal principles of behavioral medicine as a field is that well-defined treatment techniques are used for specific target symptoms or signs of illness. It is proposed that individual behavioral medicine treatment programs be called by the name of either the specific treatment utilized or of the target(s) of the intervention. It is important to ensure collaboration between the variety of treatment and research programs that would fall under this general definition of behavioral medicine, which includes consultation-liaison psychiatry. An organizational model is proposed that would combine all such programs within a multidisciplinary division of a department of psychiatry. This division might be entitled with one or both names, e.g., "consultation-liaison psychiatry and behavioral medicine." Perhaps most importantly, this new field should not promise more than it may be able to provide, particularly in trying to achieve the biopsychosocial model of medicine. Many factors have contributed to the rise of biomedicine and to the decline of personal medicine, most of them far beyond the scope and control of behavioral medicine.