In 1996 the National Institute for Occupational Safety and Health (NIOSH) engaged more than 500 organizations and individuals representing labor, industry, government, and academia, in a process to identify occupational safety and health research priorities for the United States. This process identified 21 priority research areas that became the National Occupational Research Agenda (NORA). One of these priority areas is exposure assessment methods. Methods may be defined as "tools, approaches, and strategies that are used in, or enable, the conduct of exposure assessments in the workplace." In order to explore the issues related to occupational exposure assessment, a team-the NORA Exposure Assessment Methods Team, comprised of researchers and public health professionals from industry, labor, academia, and government-was formed. To completely understand how biomarkers and research could be augmented, strengthened, developed, and applied to key exposure assessment issues, the NORA Exposure Assessment Methods Team sponsored a workshop entitled "Applying Biomarkers to Occupational Health Practice" in Santa Fe, N.M., on March 24-25, 2003. Cosponsors of the workshop included the American Industrial Hygiene Association, Society of Toxicology, and National Medical Services, Inc. The workshop was designed to bring together individuals studying worker populations, researchers developing and validating new biomarkers, and occupational health practitioners in order to foster future collaborations and identify research gaps and priorities in the application of biomarkers to occupational health practice. Since air concentrations of occupational toxicants represent only potential exposures and many workplace exposures occur through the dermal route, a primary workshop goal was to improve the understanding of biomarkers and promote their effective application in estimating exposure to occupational hazards. Biomarkers can help determine actual exposures and subsequent effects of those exposures. A second goal was to discuss prevention of occupational illness by utilizing biomarkers of exposure or early effects to determine the need to eliminate or minimize exposure. The workshop targeted multidisciplinary occupational health professionals including: biologists, chemists, toxicologists, industrial hygienists, and epidemiologists. While the first day focused on plenary presentations concerning biomarker development, application, and ethical, legal, and social issues, the second day followed a more traditional workshop model.