Background: Patient safety is a global health priority. Errors of omission, such as missed nursing care in hospitals, are frequent and may lead to adverse events. Emergency departments (ED) are especially vulnerable to patient safety errors, and the significance missed nursing care has in this context is not as well known as in other contexts. Aim: The aim of this scoping review was to summarize and disseminate research about missed nursing care in the context of EDs. Method: A scoping review following the framework suggested by Arksey and O’Malley was used to (1) identify the research question; (2) identify relevant studies; (3) select studies; (4) chart the data; (5) collate, summarize, and report the results; and (6) consultation. Results: In total, 20 themes were derived from the 55 included studies. Missed or delayed assessments or other fundamental care were examples of missed nursing care characteristics. EDs not staffed or dimensioned in relation to the patient load were identified as a cause of missed nursing care in most included studies. Clinical deteriorations and medication errors were described in the included studies in relation to patient safety and quality of care deficiencies. Registered nurses also expressed that missed nursing care was undignified and unsafe. Conclusion: The findings from this scoping review indicate that patients’ fundamental needs are not met in the ED, mainly because of the patient load and how the ED is designed. According to registered nurses, missed nursing care is perceived as undignified and unsafe.