Background: Proton-pump inhibitors (PPI) are among the most widely used drugs worldwide. However, the association between PPI use and the risk of asthma remains unclear. Objective: To investigate the association between PPI use and subsequent asthma risk. Methods: We included participants from the Taiwan National Health Insurance Research Database between 1999 and 2013. Patients who used PPIs and experienced new-onset asthma (n = 20,344) were assigned to the case cohort and matched in a 1:1 ratio with controls who did not subsequently develop asthma. PPI use was defined as > 30 cumulative defined daily doses (cDDD); non-PPI use was defined as ≤ 30 cDDDs. The Charlson Comorbidity Index (CCI) score was used for clinical prognosis and comorbidity adjustment. Multivariate Cox regression models were used for the calculation of adjusted odds ratios (OR). Results: There was a significant and dose-dependent association between PPI use and the risk of developing asthma. The adjusted ORs were 1.24 (95% confidence interval [CI], 1.15-1.33), 1.39 (95% CI, 1.28-1.50), and 1.61 (95% CI, 1.43-1.81) for the male subject with 31-120 cDDDs, 120-365 cDDDs, and >365 cDDDs, respectively, compared with PPI nonusers. Men were at higher risk of developing asthma with longer PPI use compared with women. Stratified analyses based on the PPI type showed that exposure to lansoprazole, pantoprazole, omeprazole, and esomeprazole was associated with subsequent asthma risk. Conclusion: Extended use of PPIs was found to be linked to an increased risk of asthma development. This association remained consistent across different age groups, sexes, demographic factors, indications for PPI use, CCI scores, and other atopic diseases. However, further prospective studies are required to elucidate the causal mechanisms involved.