The emergency department (ED) may represent a missed opportunity to proactively intervene upon patients at "high risk"for HIV. We sought to describe characteristics of ED HIV seroconverters (individuals who screened positive in the ED for HIV who had either (1) a previous prior negative HIV test in the electronic health record (EHR) or who (2) self-reported a prior negative HIV test) to identify a "high-risk"phenotype for pre-infection engagement. A retrospective chart-review was performed of HIV seroconverters at an academic, urban ED. General demographics, mental health illness comorbidities, and Centers for Disease Control and Prevention (CDC)-identified "high risk"factors, including intravenous drug use (IVDU) and history of sexually transmitted infection (STI) were noted. One hundred thirty total patients were identified, 48 (36.9%) with prior HER-negative test and 82 (63.1%) with self-reported previous negative test. Of total seroconverters: 100 (76.9%) were male and 77 (59.2%) were between the ages of 13-34, comparable to national rates of new HIV diagnoses. Ninety-two patients (70.8%) were Black and 16 (12.3%) had a history of IVDU, significantly increased compared with regional and national new HIV rates (p < 0.05). Fifty-two patients (40%) had an STI within 1 year before HIV-positive screen, 67 (51.5%) had a history of mental health illness, and 77 (59.2%) were uninsured. This review revealed an HIV seroconversion population disproportionately affected by race, IVDU, mental health comorbidities, and additional social factors. The ED may represent a unique opportunity for at-risk, pre-HIV exposure intervention, particularly for vulnerable populations.