There is a paucity of information about confidence with self-management in primary care practice. This study examines changes over time in patient-reported confidence with self-management on the basis of 1047 patients aged 50-69 who had common chronic diseases, bothersome pain, or emotional problems. We examined the relationship between patients' self-reported confidence, their experiences of medical care, and health outcomes after adjustment for baseline characteristics. We observed that, over a 2-year period, about a third of the patients remained confident and a third remained not confident. Change in pain or emotional problems was strongly associated with whether a patient was confident or not at the end of the follow-up period (P < .001). Persistently good confidence or improved confidence was strongly associated with measures of high-quality medical care. For patients with diabetes, persistent confidence was more often associated with control of blood glucose (P = .004) compared with the control in patients who were not as confident. Confident patients were likely to be fully engaged in everyday work and activities (P < .001). The results suggest that for the majority of patients in primary care practices, the status of their self-reported confidence with self-management persists over time. Their confidence is impacted by their pain or emotional state and strongly associated with their medical care experiences and some outcomes of care.