Background: Despite the substantial burden of asthma-related emergency department (ED) visits, there have been no recent multicenter efforts to characterize this high-risk population. Objective: We aimed to characterize patients with asthma according to their frequency of ED visits and to identify factors associated with frequent ED visits. Methods: A multicenter chart review study of 48 EDs across 23 US states. We identified ED patients ages 18 to 54 years with acute asthma during 2011 and 2012. Primary outcome was frequency of ED visits for acute asthma in the past year, excluding the index ED visit. Results: Of the 1890 enrolled patients, 863 patients (46%) had 1 or more (frequent) ED visits in the past year. Specifically, 28% had 1 to 2 visits, 11% had 3 to 5 visits, and 7% had 6 or more visits. Among frequent ED users, guideline-recommended management was suboptimal. For example, of patients with 6 or more ED visits, 85% lacked evidence of prior evaluation by an asthma specialist, and 43% were not treated with inhaled corticosteroids. In a multivariable model, significant predictors of frequent ED visits were public insurance, no insurance, and markers for chronic asthma severity (all P < .05). Stronger associations were found among those with a higher frequency of asthma-related ED visits (eg, 6 or more ED visits). Conclusion: This multicenter study of US adults with acute asthma demonstrated many frequent ED users and suboptimal preventive management in this high-risk population. Future reductions in asthma morbidity and associated health care utilization will require continued efforts to bridge these majorgaps in asthma care.