The three decennial international meetings of the Centers for Disease Control have reaffirmed the national health priority for prevention of nosocomial infections. Moreover, the past 20 years have seen the institutionalization of the infection control practitioner and hospital epidemiologist. The epidemiologic activities of these two groups have included access to medical care, identification of risk factors, and both prevention and control of adverse nosocomial events. As such, they represent experience with issues commonly referred to as quality of care. It is argued that infection control not only is now but has been from its inception the premier quality assessment program in the United States. Moreover, it is the only activity in quality assessment that has been shown to be efficacious.