Enterococci have become a significant cause of nosocomial infections in the past two decades. Moreover, acquisition of new resistance traits such as aminoglycoside resistance, beta-lactamase production, high-level resistance to penicillins due to penicillin-binding protein changes and glycopeptide resistance has dramatically limited therapeutic options for disease caused by these organisms. Although hospital-associated enterococcal infections were previously thought to be derived from endogenous flora, recent epidemiologic studies, assisted in some instances by the application of new molecular techniques, have identified both intra- and inter-hospital spread of strains of enterococci. These studies have indicated that person-to-person transmission via the hands of health care personnel may occur and have implicated inanimate objects as a possible source of enterococcal infection. It has also been shown that a major risk factor for nosocomial acquisition of enterococci is the use of antibiotics, presumably because enterococci are resistant to many of the commonly used antimicrobial regimens. With the information currently available, there can be little doubt that nosocomial infections due to enterococci will continue to be important in the future. Rapid identification of patients infected or colonized by multi-resistant enterococci, strict adherence to infection control practices, and prudent use of antibiotics all seem necessary to control and prevent nosocomial infections due to enterococci.