The Decontamination and Consequence Management Division (DCMD) of EPA's National Homeland Security Research Center (NHSRC) held its first 'Workshop on Decontamination, Cleanup, and Associated Issues for Sites Contaminated With Chemical, Biological, or Radiological Materials' at the International Trade Center Building in Washington, D.C., February 23-25, 2005. The workshop opened with a plenary session. The subsequent 31 presentations addressed 5 topics: the decontamination process, decontamination technologies, research and development, lessons learned, and radiological contamination. The speakers represented national laboratories and federal agencies such as EPA, the Department of Homeland Security, the Postal Service, the Department of Defense, the Centers for Disease Control and Prevention, and the FBI; academia; and key companies conducting research or providing decontamination technologies and services. Representatives from Great Britain provided the United Kingdom perspective on decontamination issues.