Objective To investigate the demographic and service characteristics, motive for consultation, and disposition of adult frequent users (FUs) of the largest academic hospital in the Netherlands over a 5-year period. Patients and methods This retrospective study included all patients aged 18 years and older visiting the emergency department (ED) during a 5-year period (2009-2013). Frequent ED use was defined as having four or more visits to the ED during a year. Patient and service characteristics, motive for consultation, and disposition were explored. Results Frequent ED users represented 2% of all patients who visited the ED during 2009-2013 (8% of all ED consultations). On average, each FU visited the ED five times per year. Compared with nonfrequent users (NFUs), FUs were significantly less often self-referred, less frequently transported to the hospital by ambulance, received a lower urgency code upon arrival to the ED, and more often admitted to hospital than NFUs. Complaints related to the digestive system (19%), general complaints such as fever (18%), respiratory (10%), or cardiovascular problems (10%) were the main motive for consultations of the frequent ED users. Two percent of the FUs were serial FUs (FUs during 3 or more consecutive years). Conclusion Frequent use of the ED has been depicted as inappropriate use of these services. However, our study shows that FUs consist of a relatively small number of patients and that FUs suffer from chronic, and often, severe somatic illnesses that require specialized medical care.