On May 5, 2000, the Baltimore City Health Department was notified by hospital infection-control staff of a serious systemic febrile illness in a microbiologist whose research at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) involved several pathogenic bacteria, including Burkholderia mallei, the causative agent of glanders. This report summarizes the first human case of glanders in the United States since 1945, and emphasizes the importance of considering occupational exposures among laboratory workers with a febrile illness, the difficulty of characterizing unusual agents, including potential agents of biological terrorism such as glanders using routine laboratory techniques, the appropriate isolation practices for patients who may be infected by these agents, and laboratory safety.