The predominant bacteria and antimicrobial susceptibilities were surveyed from a deployed, military, tertiary care facility in Baghdad, Iraq, serving U.S. troops, coalition forces, and Iraqis, from August 2003 through July 2004. We included cultures of blood, wounds, sputum, and urine, for a total of 908 cultures; 176 of these were obtained from U.S. troops. The bacteria most commonly isolated from U.S. troops were coagulase-negative staphylococci, accounting for 34% of isolates, Staphylococcus aureus (26%), and streptococcal species (11%). The 732 cultures obtained from the predominantly Iraqi population were Klebsiella pneumoniae (13%), Acinetobacter baumannii (11%), and Pseudomonas aeruginosa (10%); coagulase-negative staphylococci represented 21% of these isolates. These differences in prevalence were all statistically significant, when compared in chi2 analyses (p < 0.05). Antimicrobial susceptibility testing demonstrated broad resistance among the Gram-negative and Gram-positive bacteria.