Frequent attendance to the emergency department (ED) is a growing public health concern. Designing services for frequent attenders poses challenges, given the heterogeneous nature of this group. This was a two-part observational study identifying frequent attenders from ED records. The first stage studied trends and developed personas with emphasis on differentiating moderate frequent attenders (attending between 5 and 20 times per year) and extreme frequent attenders (attending more than 20 times). Stage 2 included a case note review of 100 consecutive frequent attenders. Results showed an increase in frequent attendance from 2.59% to 4.12% over 8 years. Moderate frequent attenders accounted for 97%. Of the 100 frequent attenders studied, 45% had medically unexplained symptoms (MUS), associated with younger age (p0.05). In conclusion, the ED is a useful hub for identifying frequent attenders with MUS, particularly among moderate frequent attenders; service design for this group should consider a 'whole-systems approach' with integration between primary and secondary care, including specialist liaison psychiatry services where appropriate