The CDC released revised HIV testing guidelines in 2006 recommending routine, opt-out HIV testing in acute care settings including emergency departments (ED). Patient attitudes have been cited as a barrier to implementation of routine HIV testing in the ED. We assessed patients' perceptions of HIV testing in the ED through a contextual qualitative approach. The study was conducted during a 72-h period. All adults presenting to the ED without life-threatening trauma or psychiatric crisis completed a standardized questionnaire. The questionnaire explored HIV testing history, knowledge of testing resources, and qualitative items addressing participant perceptions about advantages and disadvantages to ED testing. After completion of the interview, participants were offered a free, confidential, rapid HIV test. Among 329 eligible individuals approached, 288 (87.5%) completed the initial interview. Participants overwhelmingly (n=247, 85.8%) reported support for testing and identified increased knowledge (41%), prevention (12.5%), convenience (11.8%), and treatment (4.9%) among the advantages. Fear and denial about one's HIV status, reported by <5% of patients, were identified as the most significant barriers to ED testing. Bivariate analysis determined race and ethnicity differences between individuals completing the interview and those who refused (p<0.05). Among individuals consenting for testing (n=186, 64.6%), no positives were detected. Most patients support HIV testing in the ED, noting knowledge of status, prevention, convenience, and linkage to early treatment as distinct advantages. These data are of particular benefit to decision makers considering the addition of routine HIV testing in EDs.