Physicians are usually the first contact in the health care system for persons with dementia and their family caregivers. This paper provides a synopsis of research findings and knowledge gaps regarding interactions among these participants in the health care triad--primary care physicians, family caregivers, and persons with dementia. Research traditions that inform knowledge about health care triads and dementia care include: older patient-physician relationships; the stress-coping social-support health model that dominates family caregiver research; the social learning-self-efficacy model; and literature on the quality of medical care. An integrative framework is presented to illustrate how the quality of interaction in dementia care encounters may be influenced by specific characteristics of members of the health care triad. Domains of dementia care interaction include symptom diagnosis, symptom management, medication management, support service linkage, and emotional support. The integrative framework also links the quality of interaction in these domains with health-related outcomes relevant to each of the health care triad members. Most empirical research in this area has found that family caregivers are dissatisfied with many aspects of physicians' dementia care, but measurement techniques vary widely and little is known about how the quality of physician care is associated with health-related outcomes. Physician surveys have shown that they are least certain about the quality of support service linkage advice they provide. Virtually no research has examined how the person with dementia experiences medical care encounters with physicians and their family members. Much remains to be learned about the longitudinal experience of each member of the health care triad, and how the quality of dementia care encounters changes over the course of the disease process. In this era of rapidly expanding educational and support service interventions for persons with dementia and their family caregivers, as well as computer-based information about dementia care, the influence of these external factors on health care triad interactions and outcomes also remains to be studied.