Background: Education on inhaler technique is critical for effective asthma treatment. However, traditionally used face-to-face education is a time-consuming, costly, and often laborious. The current study evaluated the efficacy of a newly developed video-based inhaler technique education method. Methods: A total of 184 subjects with well-controlled or partly-controlled asthma were enrolled from 12 hospitals in South Korea from 30 November 2015 to 01 June 2016. Subjects were randomly divided into two groups in a 1:1 ratio; a control group that received face-to-face education, and an study group that received video education. All subjects received fluticasone propionate plus salmeterol xinafoate (Fluterol® 250/50 inhalation capsules) for 12 weeks. The primary outcome measure was forced expiratory volume in the 1st second (FEV1) at 12 weeks. The secondary outcome measures were change in FEV1 at 4 weeks, change in asthma control test (ACT) score, and changes in various inhaler technique parameters. These measures were assessed with a non-inferiority margin of 10% between the control group and the study group. Results: FEV1 was significantly improved at 12 weeks in the control group and the study group. After adjustment, FEV1 improvement was not significantly inferior in the study group compared to the control group. The secondary outcome measures, including change in FEV1 at 4 weeks, ACT score, and various parameters pertaining to inhaler technique and satisfaction at 4 and 12 weeks did differ not significantly in the two groups. In subgroup analysis of elderly subjects and subjects with well-controlled asthma, FEV1 was significantly improved at 12 weeks in the study group but not the control group. Conclusion: The newly developed video education technique investigated functioned as a suitable substitute for face-to-face education on inhaler technique (dry powder inhalation capsule) in patients with stable asthma, particularly in elderly patients and patients with well-controlled asthma.