Purpose: Asthma is a common disease that is expensive and burdensome for patients. Inhaled corticosteroids (ICS) are the most important drugs for asthma treatment and are often prescribed long-term. However, the use of ICS has been reported to increase pneumonia, though this remains controversial. We evaluated whether the use of ICS increases the risk of pneumonia in asthmatic patients using the Health Insurance Review and Assessment Service (HIRA) database in Korea. Methods: The Asthma Management Adequacy Assessment was performed by the HIRA in Korea. Patients with claimed insurance benefits for asthma disease codes and who were prescribed asthma medications more than 2 times were enrolled. Patient demographics, asthma medications, healthcare use, and complications were analyzed. Results: The total number of asthma patients was 831,613. Patients using ICS were older and had more comorbidities than those not using ICS; they also visited outpatient clinics and emergency departments, and were more often hospitalized. Pneumonia and other complications occurred more often in patients using ICS, and they used more respiratory medications, except for theophylline. Multiple logistic regression analysis showed that ICS prescription was associated with pneumonia (odds ratio, 1.38; 95% confidence interval, 1.36-1.41). Age, sex, medical care, use of secondary and tertiary hospitals, and hospitalization due to asthma in the previous year were also associated with pneumonia. Conclusions: ICS use was associated with increasing pneumonia in asthmatic patients in Korea. Therefore, it is critical to acknowledge that the use of ICS may increase the risk of pneumonia and should be meticulously monitored in asthmatics.