The aim of this study was to examine patients' motivation to participate in the Royal College of Physicians Practical Assessment of Clinical Examination Skills (PACES). An exploratory cross-sectional study was performed with data collected via telephone interviews. All patients aged 18+ who participated in PACES at University Hospitals Coventry and Warwickshire in the last two years were invited to take part; 28 patients were interviewed. Data were analysed using thematic content analysis. Motivational factors identified included the opportunity to give something back for the care received, contributing to doctors' learning processes, altruism and being able to learn more about one's own condition. Patients believed that they offered real-life experiences that cannot be provided by actors. The social environment during PACES played a large part in volunteer retention. Recruitment of patient volunteers needs to emphasise the altruistic nature of the role in assisting the learning process for doctors and the subsequent benefit for future patients.