Continuity of care is central to the philosophy and teaching of family medicine. Studies of continuity have yielded conflicting results with regard to outcomes. Reasons for this include a failure to agree upon a theoretical definition of continuity as well as failure to account for a number of influential determinants of the continuity process. It is suggested that continuity is an attitude based upon prior knowledge of and for each participant in the medical encounter. This attitude is made operational in a process consisting of five continuity dimensions: chronological, geographical, interdisciplinary, interpersonal, and informational. A working model of analysis is proposed, and the results of various studies are critically assessed. Future research in the area of continuity of care must provide reliable measures of the different continuity dimensions followed by well-controlled trials assessing the impact of these dimensions on the satisfaction, comfort, and health status of patients.