This article reports an analysis of the concept of situational awareness in nursing. Situational awareness is a fundamental and well-understood concept used to maintain operational safety in high reliability organizations; however, it has not been studied in nursing. Nurses play a critical role in providing vigilance in health care and what they do or fail to do is directly related to patient outcomes. Multiple databases, including PubMed, CINAHL, JSTOR, and Google Scholar, were searched with the term, 'situational awareness'. The primary search, used to identify all uses of the concept, did not employ date criteria. A secondary search for articles measuring situational awareness as an independent or dependent variable was completed using 2009-2011 articles. Concept Analysis. The concept of situational awareness was examined using Walker and Avant's eight step method of analysis. Three defining attributes of situational awareness include perception, comprehension, and projection. Situational awareness is defined as the perception of the elements in the environment in a volume of time and space, the comprehension of their meaning and the projection of their status in the near future. Although situational awareness is related to other terms in nursing, there is increasing recognition that the concept, which is likely a consolidation of the related terms, has an impact on healthcare professionals. Failures in perception, comprehension, and/or projection can significantly reduce the accuracy and appropriateness of patient care decisions. Therefore, as a precursor to decision making, poor or inadequate levels of situational awareness present serious threats to patient safety. Situational awareness needs to be examined in a theoretical context, studied systematically and openly recognized as a key factor in the delivery of safe patient care.