Study objective. To compare patient satisfaction with emergency department (ED) opt-in and opt-out HIV screening. Methods. We conducted a survey in an urban ED that provided rapid HIV screening using opt-in (February 1, 2007-July 31, 2007) and opt-out (August 1, 2007-January 31, 2008) approaches. We surveyed a convenience sample of patients that completed screening in each phase. The primary outcome was patient satisfaction with HIV screening. Results. There were 207 and 188 completed surveys during the opt-in and opt-out phases, respectively. The majority of patients were satisfied with both opt-in screening (95%, 95% confidence interval [CI] = 92-98) and opt-out screening (94%, 95% CI = 89-97). Satisfaction ratings were similar between opt-in and opt-out phases even after adjusting for age, gender, race/ethnicity, and test result (adjusted odds ratio 1.3, 95% CI = 0.5-3.1). Conclusions. Emergency department patient satisfaction with opt-in and opt-out HIV screening is similarly high.