Frequent visitors account for a high proportion of Emergency Department (ED) visits and costs. Some of these visits could be handled effectively in less expensive primary care settings. Effective interventions to redirect these patients to primary care depend on an in-depth understanding of frequent visitors and the reasons they seek care in the ED. The objective of this study was to explore the differences between frequent visitors and infrequent visitors who seek medical care in one urban ED, as a first step toward developing effective interventions to direct patients to effective sources of care. In structured interviews, we asked 69 frequent visitors and 99 infrequent visitors to an inner-city, adult ED about medical diagnoses, general health, depression, alcohol abuse, physical functioning, self-perceived social support, primary care and ED service use, payment method, satisfaction with their primary care physician, and demographic characteristics. Differences in responses between groups were compared using t-tests for continuous variables and chi-square for categorical variables. Frequent visitors were more likely than infrequent visitors to be insured by Medicaid (53% vs. 39%, respectively) and less likely to be uninsured (13% vs. 24%, respectively) or have private insurance (6% vs. 15%, respectively). They reported higher levels of stress, lower levels of social support, and worse general health status. They were much more likely to screen positive for depression (47% vs. 27%, respectively, p = 0.017). Frequent visitors were more likely to have a primary care physician (75% vs. 66%, respectively), and 45% of the frequent visitors had a primary care physician at the ED hospital compared to 23% of the infrequent visitors. These findings suggest the need to improve access to frequent visitors' primary care physicians, screen them for depression, and offer psychological and social services more aggressively. These findings may apply to other inner city EDs., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)