Objective : The purpose of this study is to analyze Korean patients' characteristics, who were concurrently treated with both Korean herbal medicines and Western chemical medicines using nation-wide database. Method : Using the patients sample data (HIRA-NPS 2018) provided by Health Insurance Review and Assessment Service, a group of patients who co-administered Korean herbal and Western medicines was selected, and their basic characteristics, diagnosis, and prescribed chemical medicines were analyzed. Results : Out of the 1,481,921 sample population, 17,629 patients (1.2%) were selected as a concurrent medication group. Compared to the whole sample, the concurrent medication group was composed of more women (65.8% vs. 51.1%), the more elderly people (65 or older years old) (44.5% vs. 14.6%), and the higher prevalence of chronic diseases (49.1% vs. 22.2%). The most frequent diagnosis treated with Western medicines was mental and behavioral disorders, musculoskeletal and circulatory disorders. Frequently used drugs among concurrent medication group were anti-anxiety drugs, gastric ulcer treatment drugs, and senile diseases treatment drugs. Conclusion : The evidence reported in this study is expected to provide herb-drug interaction researchers with important reference to set the priorities of research topics in the future.