Introduction: To date, there has been minimal research on advance directives (ADs) among elderly patients in Canadian emergency departments (EDs). The purpose of this study was to determine the prevalence of ADs among elderly patients visiting an urban ED. We also explored whether there were factors associated with the existence of an AD and possible barriers to having one. Methods: This prospective study ran between October and December 2008. Individuals over the age of 70 who presented to the ED between 7 am and 7 pm, 7 days a week, were considered for enrolment. Exclusion criteria included previous enrolment and inability to provide informed consent. A team of nurses who specialize in assessment of geriatric patients administered a study instrument consisting of 28 questions. Topics included demographics, level of education, medical information, and knowledge of and attitudes toward ADs. Results: The results from 280 participants, with an average age of 80.6 years, were analyzed. Thirty-five percent of participants reported that they knew what an AD was; 19.3% of participants said they had an AD, but only 5.6% brought it to the hospital; 50.7% were interested in further information regarding ADs; and 67.9% of participants felt that it was important for physicians to know their wishes about life support. Conclusion: Knowledge of ADs among elderly patients visiting an urban Canadian ED is limited and is likely a significant factor precluding wider prevalence of ADs. There is interest in further discussion about ADs in this population group.