In this review I will briefly survey the role of Pseudomonas aeruginosa, Acinetobacter baumanii, Stenotrophomonas maltophilia, and Burkholderia cepacia as opportunistic pathogens. A common feature of these organisms is intrinsic resistance to multiple antibiotics. All of these organisms can be recovered from the environment, commonly cause device-related infections, are often resistant to disinfectants, and have the potential to spread from patient to patient via fomites or the hands of medical personnel. Newer clinical syndromes will be emphasized, including the increasing importance of P. aeruginosa infections in patients with AIDS, as well as the role of carbapenems in selecting for A. baumanii and S. maltophilia and the unique niche of B. cepacia in patients with cystic fibrosis.