The study purpose was to identify human performance factors that characterized novice nurse near-miss/adverse-event situations in acute-care settings. Increased focus on recruitment and retention of newly graduated registered nurses (RNs) in light of patient safety improvement goals will challenge healthcare educators and administrators. What we are beginning to learn about human performance issues during real work situations from patient safety research provides information related to human performance in complex environments that may guide education and system supports for novice RNs. Data collected during 8 retrospective interviews of novice RNs about details surrounding their individual near-miss or adverse event were analyzed for common themes. Nine themes were identified. Seven themes were present in at least 7 of the 8 cases and included environmental and social issues, as well as novice lack of expertise. Findings suggest that support for novice nurses in acute care environments requires attention to the following: consistent availability of expertise in light of workload unpredictability, the social climate regarding expectations of novice performers, realistic expectations of novice decision-making ability during complex situations even up to a year after graduation, and strategies to recognize and intervene when novices are at risk for error.