The emergency department (ED) serves as the entry point into the U.S. health care system for many patients with limited English proficiency (LEP). This paper reviews the literature on language interpreter utilization in the ED setting. We focused on three clinical issues related to professional language interpretation: (1) patient satisfaction, (2) health care delivery, and (3) current interpreter utilization practices. Compared with-English speaking patients, LEP patients report less satisfaction with medical encounters, have different rates of diagnostic testing, and receive less explanation and follow-up. Although professional interpretation has been associated with improvements in patient satisfaction, communication, and health care access, these services are largely under-utilized in ED settings. Reliance on untrained ad hoc interpreters, perceived time and labor associated with obtaining and working with an interpreter, and costs of implementing professional interpreter services serve as barriers to implementation and utilization.