Prevention of medication errors in emergency departments is a growing focus of safety efforts, due in part to a National Patient Safety Goal targeting medication errors. Clinical pharmacists effectively prevent medication errors in the inpatient setting, but their role in the emergency department is less studied. This systematic review of 17 published studies characterizes roles played by emergency pharmacists, including medication reconciliation, error prevention, and a variety of other duties. Another study (not included in this review) found a significant reduction in medication errors after assigning pharmacists to review medication orders in the emergency department.