BACKGROUND: Patient assessment is an essential nursing intervention that reduces the incidence and impact of errors and preventable adverse events in emergency departments (EDs). This paper reports on a key finding of the ED nurse component of a larger study investigating how registered nurses manage 'discontinuities' or 'gaps' in patient care. METHODS: The larger study was undertaken as a naturalistic inquiry using a qualitative exploratory descriptive approach. Data were collected from a criterion-based purposeful sample of 71 nurses, of which 19 were ED nurses, and analysed using content and thematic analysis strategies. RESULTS: The component of the study reported here revealed that ED nurses used 'hands-on', head-to-toe assessment to manage gaps in patient care. Examination of the data revealed three key dimensions of patient assessment in the ED: (i) assessment is the 'bread and butter' of emergency nursing; (ii) 'hands-on' assessment techniques are irreplaceable and, (iii) patient assessment is undervalued in EDs. CONCLUSIONS: The findings of this study reaffirm the role of 'hands-on' observation and assessment in creating safety in EDs. Further research and inquiry is needed to determine how health care systems can provide the conditions for ensuring that 'hands-on' assessment occurs.