The Queens Ground Zero Worker Health Watch proposes a longitudinal assessment of the health of Ground Zero workers that is designed: a) to characterize changes in the health status and the development of new health conditions among Ground Zero and related workers, b) to provide Ground Zero workers with current state of the art knowledge, individually and in aggregate, about the health effects of working at Ground Zero, and c) to ensure appropriate referral and follow-up for health conditions that are detected in the screening program. The Queens Ground Zero Worker Health Watch proposes to serve as a Clinical Center for a minimum of 700 workers within the overall World Trade Center (WTC) Responder Health Consortium. The Clinical Center is conveniently located for the approximately 23percent of participants in the baseline screening program that live in Queens and immediately adjacent areas. The credibility and expertise of the Clinical Center proposed by Queens College is demonstrated by the baseline examination of 600 Ground Zero workers by Queens College as part of the WTC Worker and Volunteer Medical Screening program (2003-present);the medical screening of 415 day laborers/building clean-up workers near Ground Zero by Queens College in early 2002;and the national medical screening of 9,200 Department of Energy workers by Queens College in cooperation with PACE International Union between 1999 and 2004. Proposed mechanisms to minimize participant attrition and to maintain program loyalty over time will include a program newsletter, group educational sessions, and a WTC Worker Advocacy Group. In addition, Queens College has a demonstrated capacity to work collaboratively with other medical institutions, unions, the NYC Health Department, and other agencies that have been essential to the documentation of health effects of Ground Zero workers. Queens College, thus, anticipates that it will serve as a valuable clinical, scientific, and intellectual resource to Ground Zero workers and to the World Trade Center Responder Health Consortium.