Purpose:  The purpose of the study was to empirically test items of a new measure designed to assess person-directed care (PDC) practices in long-term care. Design and Methods: After reviewing the literature, we identified five areas related to PDC: personhood, comfort care, autonomy, knowing the person, and support for relationships. We also identified an additional component of environmental support. We developed items to reflect the constructs, and then a series of lay and professional experts in the field reviewed the items for face validity. We distributed the resulting 64-item PDC and Environmental Support for PDC measure to direct care workers and nursing, administrative, and other staff from a range of long-term settings across Oregon, culminating in a sample size of 430 participants from eight sites. We employed exploratory factor analyses to reveal the underlying structure of the measure. Results: After we dropped 14 items from the measure, it attained good simple structure, revealing five PDC constructs as previously theorized and three Environmental Support constructs: Support for Work With Residents; Person-Directed Environment for Residents, and Management/Structural Support. All constructs were conceptually distinct and internally consistent, and, as expected, all were positively correlated. Implications: The PDC measurement tool developed through the Better Jobs Better Care demonstration program funded by the Atlantic Philanthropies and Robert Wood Johnson Foundation is an important step toward operationalizing the philosophies inherent in the concepts of PDC and is expected to be a useful tool in evaluating successes in meeting PDC goals and in prompting further research regarding PDC and its consequences for resident and client outcomes.