Study objective We determine whether there are differences in role-related communication patterns in the emergency department (ED). Methods This was an observational study of a metropolitan ED. Four medical officers and 4 nurses were observed for 19 hours and 52 minutes. Communication load was measured by proportion of observed time in communication, proportion of concurrent communication events, and proportion of interruptions. Results Eight hundred thirty-one communication events were identified, an average of 42 events per person per hour. Eighty-nine percent of clinicians' time was spent in communication. Synchronous communication channels, involving face-to-face or telephone conversations, were used in 84% of events. One third of communication events were classified as interruptions, averaging 15 interruptions per person per hour. Senior medical and nursing staff experienced higher rates of interruption than junior medical staff and registered nurses with an allocated patient load. Conclusion There was considerable variation in communication loads on clinical staff occupying different roles in the ED. Medical registrars had a high proportion of interruptions and spent the most time dealing with interruptions. These new data suggest some clinical roles may be at higher risk of communication overload than those of the general clinical population.