Background: Recent studies suggest that dipeptidyl peptidase-4 (DPP-4) inhibitors increase the risk of developing bullous pemphigoid (BP). Population-based studies on the association between DPP-4 inhibitors and BP are limited. Objectives: To characterize the association between the use of DPP-4 inhibitors and an increased risk of developing BP. Methods: A nationwide retrospective case-control study was performed using Korean insurance claims data from 2012 to 2016. Results: 670 case patients (with diabetes mellitus and BP) and control patients (with only diabetes mellitus) were included our study; the mean age was 75.3 years and 51.0% of subjects were male. The number of patients with diabetes and BP more than doubled during the study period. DPP-4 inhibitors was associated with a significant increase in the risk of developing BP (adjusted odds ratio [aOR], 1.59; 95% CI, 1.26-2.00; P<.001); among all DPP-4 inhibitors used in Korea, the highest aOR was associated with the use of vildagliptin (aOR, 1.85; 95% CI, 1.34-2.54; P<.001). Subgroup analyses revealed: i) a significant association in male patients (aOR, 1.91; 95% CI, 1.39-2.63; P<.001) and ii) that vildagliptin was the most high-risk DPP-4 inhibitor (aOR, 2.75; 95% CI, 1.75-4.30; P<.001). Conclusion: DPP-4 inhibitors are associated with a significantly increased risk for the development of BP in patients with diabetes. Of the DPP-4 inhibitors available in Korea, vildagliptin carries the highest risk, particularly in male patients.