This systematic review was conducted to evaluate any interventions to prevent incident delirium, or shorten the duration of prevalent delirium, in older adults presenting to the emergency department (ED). A literature search of 11,900 studies of which 10 met study inclusion criteria demonstrated few interventions initiated in the ED were found to consistently reduce the incidence or duration of delirium.  The use of melatonin in the selected indications, such as overnight stay in the ED, could be tested. Multi-factorial programs show the most promise in reducing delirium-related outcomes. Still, sustained, multi-center research is required to assess whether such interventions, whether the entire program or a part of it, are feasible and effective in the ED. Older adults with hip fracture appear to be a target population in which investigators used both pharmacological and non-pharmacological interventions; however, interventions studied to date have not demonstrated a significant impact. The prevention and treatment of delirium is an opportunity for the improvement of patient care in the ED and requires further research.