This report updates the investigation of bioterrorism-related anthrax and the provision of antimicrobial prophylaxis to exposed persons and highlights CDC assistance to other countries investigating cases of bioterrorism-related anthrax. Since November 7, 2001, CDC and state and local public health agencies have identified no new cases of bioterrorism-related anthrax. As of November 14, a total of 22 cases of anthrax has met the CDC case definition; 10 were confirmed inhalational anthrax, and 12 (seven confirmed and five suspected) were cutaneous anthrax. Investigation of a case of inhalational anthrax in a hospital stock room worker aged 61 years in New York City (NYC) found no evidence of anthrax contamination at the work site or home; the source of exposure is unknown. Environmental clean-up of contaminated facilities continues, and surveillance for newcases of bioterrorism-related anthrax is ongoing in Delaware (DE), District of Columbia (DC), Florida (FL), Maryland (MD), New Jersey (NJ), NYC, Pennsylvania (PA), Virginia (VA), and other states.