© 2020 Background: Patients who return to the Emergency Department (ED) for the same complaint are known to be at risk of adverse events. Monitoring of return visits is considered a way to measure the quality of care provided in the ED, although the most commonly used benchmark of 48 h lacks evidence. This study aimed to describe the incidence, characteristics and outcomes of patients with unplanned return visits. The study also aimed to determine the capture rate of the 48-h benchmark using an all-inclusive method of return visit identification. Methods: A retrospective cross-sectional study was conducted across three EDs in Sydney, New South Wales from July 1st, 2017 to June 30th, 2018. Visits that occurred within 28 days with the same or similar presenting complaint following discharge from the ED were classified as a return visit. Data were grouped by index and return visit. Descriptive statistics were used to summarise incidence, patient characteristics and outcomes for all presentations. Categorical data were analysed using Chi square tests. Continuous data were analysed using Mann–Whitney when data were not normally distributed and t-tests when normally distributed. Results: Of all ED presentations (n = 164,598), 5860 (3.6%) were identified as a return visit. Return patients were younger than non-return patients, but those that required admission were older (43 vs 33 years, p = <0.01). Abdominal problems were the most common reason for return followed by urological and mental health. The median time to return was 64:51 h (IQR 20:35–226:37). Only 43% of return visits occurred within 48 h. Return visits to a different ED accounted for 13.2% of return visits. Conclusion: More than half of ED return visits are missed when the existing benchmark of 48 h is used. Current policy makers should consider increasing the 48-h benchmark to more accurately reflect the incidence of return visits. Further investigation into the causal factors for return visits is warranted, particularly in patients with abdominal, urological or mental health complaints.