Objective: Enhancing self-efficacy is central to programmes promoting self-care and self-management. However, little is known about older people's self-efficacy in doctorpatient interactions. This paper investigates lifestyle, medical and demographic factors associated with self-efficacy in doctor-patient interactions in older people in general practice. Methods: A cross-sectional analysis of data from a randomised controlled trial of older people was conducted in a health risk appraisal study in London. Self-efficacy was measured using the Perceived Efficacy in Patient-Physician Interactions Questionnaire. Results: Older people with higher self-efficacy were significantly more likely to report having had recent preventive care measures such as recent blood pressure measurement and influenza immunisation. Women were less likely to have higher self-efficacy than men. Older people were significantly less likely to have high self-efficacy if they reported having poor memory, low mood, limited activities due to fear of falling, basic education, difficulties with at least one activity of daily living, reduced physical activity, living alone, or risk of social isolation. Conclusion: A third of people had low self-efficacy in doctor-patient interactions. They appear to be a vulnerable group. Low self-efficacy in interactions with doctors may be a symptom or a characteristic of older people who experience social isolation and depression. Policies that depend on enhancing self-care and self-management need to consider the large number of older people with low self-efficacy in using medical services, and understanding characteristics in older people associated with lower confidence in doctorpatient interactions may be useful in clinical practice and research.