In the debate about which specialty should provide primary care for adults in the United States, part of the issue is the type of training given to the primary care provider and the overall quality of care provided by those who complete the training. This paper presents a literature review that summarizes the quality of care of family physicians by outcome and process measures. Studies in the literature are flawed by methodologic weaknesses, including the frequent lumping of all general and family physicians as a group and the general lack of description of the physicians involved. Some studies measuring the process of care indicate poorer process by family physicians or general practitioners, such as recording fewer medical process criteria used to measure quality of care. The quality of care by outcome measures, however, appears to be similar to that of other specialties. In general, the study of quality of care is in its infancy, and further work needs to be done to assess what training is needed to produce the highest quality primary care physicians.