IMPORTANCEOpioid prescriptions for treatment of pain in emergency departments (EDs) are associated with long-term opioid use. The temporal pattern of opioid prescribing in the context of the opioid epidemic remains unknown. OBJECTIVE To examine the temporal pattern of opioid prescribing within an ED for varying pain conditions between 2009 and 2018. DESIGN, SETTING, AND PARTICIPANTS A population-based, cross-sectional study was conducted at the ED of an urban academic medical center. All patients treated within that ED between January 1, 2009, and December 31, 2018, were included. MAIN OUTCOMES AND MEASURESThe proportion of patients prescribed an opioid for treatment of pain in the ED temporally by condition, condition type, patient demographics, and physician prescriber.