Objective: Patients with chronic obstructive pulmonary disease (COPD) commonly present with cardiovascular disease (CVD). We investigated the association between COPD exacerbations and major cardiovascular (CV) events in a COPD population with a history of CVD.Methods: This population-based and register-based cohort study identified all Danish COPD patients aged >= 40 years who visited a hospital-based, pulmonary outpatient clinic for COPD between 1st January, 2010, and 31st December, 2016, from a nationwide COPD registry. Patients with a history of a major CV event 36-6 months prior to their COPD measurement date and no CV event 6 months before this date were included. During a 6-month assessment period, the risks of a new CV event (hospitalization with fatal/ non-fatal stroke, myocardial infarction, or heart failure) and moderate and severe COPD exacerbations were evaluated. Odds ratios with 95% confidence intervals for CV events and death were estimated using adjusted logistic regression models.Results: Of the 1501 COPD patients included, 55% experienced a COPD exacerbation and 13% experienced both an exacerbation and a CV event during follow-up (6 months). The odds of a CV event were 1.5 times higher in patients with a moderate exacerbation and more than 6-times higher in those with a severe exacerbation vs patients with no exacerbation(s). The majority of CV events occurred within 30 days post exacerbation in patients who experienced both an exacerbation and a CV event. In total, 113 patients died during the study period: 28% of deaths were caused by CVD and 72% by reasons other than CVD, mostly COPD.Conclusion: In patients with known CVD, severe COPD exacerbations are associated with increased odds of major CV events that occur within 30 days post exacerbation, highlighting the need to prevent exacerbations in COPD patients with concomitant CVD to potentially improve both respiratory and CV health.