OBJECTIVE: There are growing concerns regarding the lack of COVID-19 pandemic response capacity in already overwhelmed emergency departments (EDs), and lack of proper isolation facilities. This study evaluated the effectiveness of the negative pressure isolation stretcher (NPIS) and additional negative pressure isolation rooms (NPIRs) on the maintenance of emergency care capacity during the COVID-19 outbreak. METHODS: A before and after intervention study was performed between February 27, 2020 and March 31, 2020 at the ED of Chungbuk National University Hospital, Cheongju, South Korea. A total of 2455 patients who visited the ED during the study period were included. Interventions included the introduction of the NPIS and additional NPIRs in the ED. The main outcome of the study was frequency of medical cessation. Secondary outcomes were the average number of ED visits and lengths of stay. RESULTS: After the intervention, average frequency of medical cessation was significantly decreased from 1.6 times per day (range 0-4) in the pre-intervention period to 0.6 times per day (range 0-3) in the post-intervention period (p-value <0.01). On the other hand, the number of patients visiting the ED increased significantly from 67.2 persons per day (range 58-79) pre-intervention to 76.3 persons per day (range 61-88) post-intervention (p value <0.01). However, there were no statistically significant differences in the average ED length of stay across the study phases (p value = 0.50). CONCLUSIONS: This intervention may provide an effective way to prepare and meet the ED response needs of the COVID-19 pandemic.