This study characterizes the use of complementary and alternative medicines (CAM) among ED patients and demonstrates patterns of healthcare utilization among users and nonusers of CAM therapies. A cross-sectional observational study was performed by administering questionnaires to ED patients at a university teaching hospital. Of the 356 patients surveyed, more than half (55%) had tried at least one complementary and alternative therapy within the past 12 months and 17% had tried CAM for their presenting medical problem. The use of CAM interventions varied significantly among different demographic groups. The number of ED visits over the past year did not differ between the users and nonusers of CAM, but those using alternative therapies did have more visits to outpatient physicians over the past 12 months (7.8 vs. 5.2; 95% confidence interval [CI], 7–4.6; P <.01). After controlling for age, ethnicity, education level, religion, income, and self-report of overall health status, users of CAM had more frequent visits to outpatient physicians (odds ratio [OR], 1.06; 95% CI, 1.02–1.1; P <.01), had no difference in their rates of hospitalization, but trended toward spending fewer days in the hospital when they were admitted (OR, .96; 95% CI, .92–1.0; P = .06). Complementary and alternative medicines are being used by a majority of ED patients with a significant number having used CAM for their presenting complaint before visiting the ED. CAM users do not differ in their utilization of the ED when compared with nonusers, but do have a significantly increased frequency of outpatient physician visits.