Emergency departments (EDs) provide a disproportionate amount of care to disenfranchised and vulnerable populations. We examined social support levels among a diverse population of adults seeking ED care for acute respiratory tract infections. A convenience sample of adults seeking care in 1 of 15 US EDs was telephone interviewed 1 to 6 weeks postvisit. The Multidimensional Scale of Perceived Social Support (7-point Likert) assessed social support across 3 domains: friends, family, and significant others. Higher scores indicate higher support. Of 1104 subjects enrolled, 704 (64%) completed the follow-up interview. Factor analysis yielded 3 factors. Mean social support score was 5.54 (SD 1.04). Female sex, greater household income, and better health status were independently associated with higher levels of social support. Social support levels among adults seeking care in the ED for acute respiratory tract infections are similar to general population cohorts, suggesting that social support is not a strong determinant of health care seeking in EDs.