The purpose of this study was to investigate the relationships among the self-efficacy, professional commitment, and job satisfaction of diabetic health-care personnel. The research design was cross-sectional. Three teaching hospitals, one from each of northern, middle and southern parts of Taiwan, were selected for data collection and used questionnaires to collect data; 202 participants were recruited. The demographic data for job title and job satisfaction were not significantly different (F = 2.13, P = 0.090). Self-efficacy was significantly positively correlated with professional commitment (r = 0.29, P = 0.000) and with job satisfaction (r = 0.14, P = 0.041). A total of 34.1% of the variance in job satisfaction was explained by age, years of service in the medical or nursing field, the actual number of years caring for patients with diabetes, self-efficacy, and professional commitment. Understanding the self-efficacy and professional commitment of medical and nursing personnel can help increase job satisfaction and improve the quality of medical and nursing care.