Background: Emergency departments (EDs) are the primary source of healthcare for many patients diagnosed with sexually transmitted infections (STIs). Expedited partner therapy (EPT), treating the partner of patients with STIs without an exam of the partner, is an evidence-based practice for patients who might not otherwise seek care. Little is known about EPT use in the ED. We describe the knowledge, attitudes, and practices of EPT in a national survey of academic EDs medical directors. Methods: A cross-sectional internet survey of ED medical directors using the Academy of Academic Administrators of Emergency Medicine (AAAEM) Benchmarking Group from July through September 2020. Primary outcomes were EPT awareness, support, and use. The survey also examined barriers and facilitators. Multivariable regressions explored predictors of EPT support. Results: Forty-eight of 70 (69%) medical directors responded, representing EDs with a median volume of 67,840 patients/year. Awareness of EPT was high (73%), but fewer knew how to prescribe it (38%), and only 19% of EDs had implemented EPT. Most (79%) supported EPT and were more likely to if they were aware of EPT (89% vs. 54%) p=0.01. Of non-implementers, 41% thought EPT was feasible, and 56% thought departmental support would be likely. Of potential barriers, ED directors were most concerned about legal liability (25% moderately to extremely). Benefits of EPT were rated with similar importance, with preventing sequelae of untreated STIs most frequently rated as extremely important (44%). Linear regression showed increased years in practice, and ED's proportion of Medicaid patients was significantly positively associated with support for EPT. Conclusion: ED medical directors expressed strong support for EPT and reasonable levels of feasibility for implementation but low utilization. Our findings highlight the need to identify mechanisms for EPT implementation and develop ED-tailored implementation tools to bolster this practice.