Abstract: Background: Failure to identify and respond to clinical deterioration is an important measure of patient safety, hospital performance and quality of care. Although studies have identified the role of patient, system and human factors in failure to rescue events, the role of ‘inattentional blindness’ as a possible contributing factor has been overlooked. Objective: To explore the nature and possible patient safety implications of inattentional blindness in critical care, emergency and perioperative nursing contexts. Methods: Analysis of four case scenarios drawn from a naturalistic inquiry investigating how nurses identify and manage gaps (discontinuities) in care. Data were collected via in-depth interviews from a purposeful sample of 71 nurses, of which 20 were critical care nurses, 19 were emergency nurses and 16 were perioperative nurses. Case scenarios were identified, selected and analysed using inattentional blindness as an interpretive frame. Results: The four case scenarios presented here suggest that failures to recognise and act upon patient observations suggestive of clinical deterioration could be explained by inattentional blindness. In all but one of the cases reported, vital signs were measured and recorded on a regular basis. However, teams of nurses and doctors failed to ‘see’ the early signs of clinical deterioration. The high-stress, high-complexity nature of the clinical settings in which these cases occurred coupled with high cognitive workload, noise and frequent interruptions create the conditions for inattentional blindness. Conclusion: The case scenarios considered in this report raise the possibility that inattentional blindness is a salient but overlooked human factor in failure to rescue events across the critical care spectrum. Further comparative cross-disciplinary research is warranted to enable a better understanding of the nature and possible patient safety implications of inattentional blindness in critical care nursing contexts.