Accurately measuring trust between patients and health care providers is important because low patient-provider trust can lead to poor treatment adherence and negative health outcomes. To measure patient-provider trust, we developed the Health Care Relationship (HCR) Trust scale. Findings from our initial use of the scale suggested the need to examine the scale's psychometric performance in a larger sample of adults with various chronic health conditions. We therefore examined the psychometric properties of the HCR Trust Scale in a random sample of adult primary care patients. Thirteen of the original 15 items fit the data best; a single-factor structure explained 67% of the variance in patient-provider trust. The Cronbach's alpha for the 13-item HCR Trust Scale-Revised was .96.