BACKGROUND: Inhaled corticosteroids (ICS) are effective in managing asthma and chronic obstructive pulmonary disease (COPD) but increase the risk of pneumonia. Benzodiazepines (BZD), commonly prescribed for comorbid psychiatric disorders in asthma or COPD patients, are also associated with pneumonia. This study investigates the risk of pneumonia associated with the concomitant use of ICS and BZD. METHODS: Data from the FDA Adverse Event Reporting System from Q4 2013 to Q3 2023 were extracted. Reports involving asthma or COPD patients were included. Disproportionality analysis and logistic regression analysis were performed to assess the risk of pneumonia associated with the combined use of ICS and BZD. Additive and multiplicative models were used to further confirm the results. Additionally, subgroup analyses were conducted based on gender, age, and disease type. RESULTS: A total of 238,411 reports were included. The combined use of ICS and BZD was associated with a higher reporting of pneumonia (ROR: 2.41, 95% CI 2.25-2.58). Using additive and multiplicative methods, the results remained significant. The strongest risk signals were observed in specific drug combinations, such as mometasone with clonazepam, budesonide with temazepam, and mometasone with zopiclone. Subgroup analyses showed higher pneumonia risks in females, patients over 60 years old, and those with asthma. CONCLUSION: Our findings identified a significantly elevated pneumonia risk with the combined use of ICS and BZD. These results highlighted the necessity for cautious co-prescription of ICS and BZD and suggested the need for more comprehensive clinical studies to assess this interaction.