Background. Occupational therapy facilitates care for complex frail emergency department (ED) patients who may have unscheduled return visits (URVs). Purpose. To determine the prevalence of frailty amongst ED patients referred to occupational therapy and if frailty affected the rates and reasons for URVs. Methods. A mixed-methods health records review was conducted of older adults referred to an ED-based occupational therapy program. Findings. Most patients were frail (60.6%). 31.0% of patients discharged home had a URV within 30 days, with no difference in URV rates between frail and non-frail populations. Providing occupational therapy education reduced the frequency of URVs. Frail patients had complex reasons for their URVs, including functional, social/environmental, safety concerns, and/or “failure to thrive”. Occupational therapy ED patients were typically vulnerable to moderately frail, dependent in some activities of daily living, and complex. Implications. ED-based occupational therapists must be aware of their patient's frailty and risk of URVs.