Safety concerns are a barrier to prescribing benzodiazepines (BDZs) and opioids in interstitial lung disease (ILD). We therefore examined the association of BDZs and opioids on risk of admission to hospital and death. We conducted a population-based longitudinal cohort study of fibrotic ILD patients starting long-term oxygen therapy in Sweden between October 2005 and December 2014. Effects of BDZs and opioids on rates of admission to hospital and mortality were analysed using Fine-Gray and Cox regression while adjusting for potential confounders. We included 1603 patients (61% females). BDZs were used by 196 (12%) patients and opioids were used by 254 (15%) patients. There was no association between BDZs and increased admission. Treatment with high- versus low-dose BDZs was associated with increased mortality (subdistribution hazard ratio (SHR) 1.46, 95% CI 1.08-1.98 versus 1.13, 95% CI 0.92-1.38). Opioids showed no association with increased admission. Neither low-dose opioids (30 mg��day ���1 oral morphine equivalent) (SHR 1.18, 95% CI 0.96-1.45) nor high-dose opioids (>30 mg��day ���1 oral morphine equivalent) (SHR 1.11, 95% CI 0.89-1.39) showed association with increased mortality. This first ever study to examine associations between BDZ and opioid use and harm in ILD supports the use of opioids and low-dose BDZs in severely ill patients with respiratory compromise.