Purpose: This study aimed to evaluate the usefulness of a behavioral cue checklist (BCC) containing 17 items developed by Wilkes et al. (2010) for identifying potentially violent patients in emergency departments. Methods: This was a prospective observational study to evaluate the usefulness of the Korean version of a BCC (K-BCC) as an assessment tool for predicting patient violence in emergency departments, and was conducted over 4 weeks in a regional emergency medical center located in B City. A total of 1,324 patients were finally analyzed. Results: Logistic regression analysis was performed to investigate whether each item of the K-BCC predicts violence, and a parsimonious set of 8 statistically significant items was selected for the tool. Receiver operating characteristic analysis of the BCC showed that the area under the curve was .97 (95% confidence interval: .94~1.0). The sensitivity, specificity, positive predictive value, and negative predictive value at the cut-off score of 2 were 75.6%, 98.9%, 68.2%, and 99.2%, respectively. Conclusion: The K-BCC was found to be useful in predicting patient violence toward emergency department staff. This tool is simple, and fast to use and can play a significantly role identifying potentially violent patients. Owing to this advance identification, this tool can be helpful in preventing the potential for violence from manifesting as violent behaviors.