We evaluated the relationship between new selective serotonin reuptake inhibitor (SSRI) or serotonin-noradrenaline reuptake inhibitor (SNRI) drug use and respiratory-related morbidity and mortality among older adults with chronic obstructive pulmonary disease (COPD).This was a retrospective population-based cohort study using heath administrative data from Ontario, Canada. Individuals aged ≥66 years, with validated, physician-diagnosed COPD (n=131 718) were included. New SSRI/SNRI users were propensity score matched 1:1 to controls on 40 relevant covariates to minimise potential confounding.Among propensity score matched community-dwelling individuals, new SSRI/SNRI users compared to non-users had significantly higher rates of hospitalisation for COPD or pneumonia (hazard ratio (HR) 1.15, 95% CI 1.05-1.25), emergency room visits for COPD or pneumonia (HR 1.13, 95% CI 1.03-1.24), COPD or pneumonia-related mortality (HR 1.26, 95% CI 1.03-1.55) and all-cause mortality (HR 1.20, 95% CI 1.11-1.29). In addition, respiratory-specific and all-cause mortality rates were higher among long-term care home residents newly starting SSRI/SNRI drugs versus controls.New use of serotonergic antidepressants was associated with small, but significant, increases in rates of respiratory-related morbidity and mortality among older adults with COPD. Further research is needed to clarify if the observed associations are causal or instead reflect unresolved confounding.