Health care–associated infections (HAIs) are one of the most common complications of care.1 HAIs are of particular concern in critically ill patients; according to estimates, almost half a million incidents of HAI occur each year in intensive care units (ICUs) alone.2 Increased susceptibility to HAIs in ICU patients is attributable in part to precarious clinical conditions,3 depressed immune function,4 and the need for invasive monitoring to ensure appropriate provision of care. The Centers for Disease Control and Prevention has made specific recommendations to aid in the prevention of central catheter–associated bloodstream infections (catheter-associated BSIs), urinary tract infections (UTIs), and ventilator-associated pneumonias (VAPs).5 The recommendations focus on specific actions to be implemented by staff members, including hand hygiene, aseptic insertion of catheters, and placing patients in a semirecumbent position during intubation.5 As the largest group of ICU clinicians who provide direct patient care, critical care nurses are well positioned to implement the recommendations and monitor patients for HAIs. Development of HAIs in acute care areas has been linked to organizational factors, such as nurse staffing.6,7 In addition to staffing, a quality work environment—another organizational component of hospital nursing care—presumably provides critical care nurses the time and resources necessary to provide HAI preventive care. Evidence on the relationship between nurse organization, particularly the work environment, and HAIs in critical care units is limited. The work environment is defined as the organizational characteristics of the workplace that facilitate or constrain professional nursing practice.8 Researchers have suggested that providing nurses with better resources and more time for patient care within a flat organizational management structure might improve the patient-nurse interaction and quality of care. Indeed, the American Association of Critical-Care Nurses9 has endorsed the importance of a healthy work environment and the potential link between the environment and patient safety. In 2 descriptive studies,10,11 members of the association were surveyed on their perceptions of the workplace and the quality and safety of patient care. Approximately 86% of respondents reported that their unit provided excellent or good-quality care, but one quarter of these nurses indicated that the quality of care in their units during the past year had become worse.10 Almost half a million health care–associated infections occur each year in intensive care units. Inconsistencies noted in critical care nurses’ reports of quality and safety are also reflected in the ICU literature. Better communication between ICU nurses and physicians has been linked to fewer nurse-reported medication errors and greater job satisfaction.12,13 Greater variation in effective communication among providers in ICUs was associated with greater rates of VAP.14 Additionally, scores on the composite Practice Environment Scale of the Nursing Work Index (PES-NWI), a commonly used measure of nurses’ work environment, was not predictive of nurse-assessed VAP and catheter-associated sepsis.12 However, a more positive organizational climate, a concept similar to the work environment, was significantly associated with higher odds of catheter-associated BSIs and lower odds of UTIs.15 The mixed evidence, limited in part by small sample sizes, restricted generalizability,12,15 and inconsistent reports of nurses10 indicate that more investigation is needed to understand how the critical care work environment may affect the frequency of HAIs. The purpose of our study was to describe critical care work environments and to determine whether or not the environments were associated with nurse-reported HAIs in a sample of critical care nurses in more than 300 hospitals in 4 states. We hypothesized that nurses in better work environments would be less likely to report frequent HAIs than would nurses in less favorable environments. We posited that a better critical care work environment would offer nurses more time, resources, and support, thereby increasing the number, duration, and quality of nurse-patient interactions. These potentially more frequent, longer, and better quality interactions might enable nurses to use adequate aseptic technique, enhance monitoring of intravenous insertion sites, identify clinical changes early, and prevent the development of a HAI.