The domain of health psychology is the intersection of the total health system with all of psychology. The competencies of psychologists include research and practice regarding the individual, interventions in situations using a variety of methods, and directing these interventions to the range of health care problems. Examples are described, including areas where health psychologists could direct their attention. Any well trained psychologist can work effectively in some aspect of the health care system, provied he has sufficient understanding of the system to gain entry and can represent system prenomena in psychological terms. An intercultural perspective will facilitate discovery of important variables that could be misperceived from a unicultural perspective, thus contributing to the theoretical and practical of health psychology.