The Patient-Reported Outcomes Measurement Information System (PROMIS), which seeks to improve and standardize tools of clinical research across multiple NIH Institutes, is a 5-year project that is part of the US National Institutes of Health (NIH) Roadmap Initiative. More information about the NIH Roadmap Initiative is available on the Internet (go to http://nihroadmap.nih.gov). Briefly, PROMIS began in late 2004, with the formation of a multicenter cooperative network of US academic institutions and the NIH. Its purpose is to improve the tools for measuring patient-reported health outcomes in clinical research. Specifically, PROMIS collaborators are constructing and making accessible item banks that are useful in measuring key health status concepts across a wide variety of chronic conditions. The concepts are five generic health-related QOL domains: emotional distress, fatigue, pain, physical functioning, and social role participation. The approach is to develop a set of publicly-available computerized adaptive tests (CAT) for use in measuring these domains for the clinical research community. The PROMIS network includes clinicians, clinical researchers, and measurement experts and is organized around six primary research site (PRS) grants—Duke University, Stanford University, Stony Brook University, University of North Carolina at Chapel Hill, University of Pittsburgh, and University of Washington—and a Statistical Coordinating Center (CORE, Evanston Northwestern Healthcare and Northwestern University). NIH scientists also participate in the PROMIS network, and a Scientific Advisory Board oversees PROMIS and evaluates its progress toward its goals.