BACKGROUND: Exacerbation of COPD (ECOPD) has been linked to increased cardiovascular disease (CVD) risk within the first year, yet longer term risk is unclear. We aimed to investigate the short-term and long-term CVD risks after severe ECOPD. METHODS: Patients with self-reported or spirometry-detected COPD at baseline and patients with newly documented COPD during follow-up were included from the China Kadoorie Biobank. Multiple data sources were used to collect information on ECOPD hospitalisation and CVD incidence during follow-up. Time-dependent Cox regression models were used to estimate the hazard ratios and 95% confidence intervals for each risk period following ECOPD compared to the baseline period. RESULTS: Of the 46 514 patients included, 48.2% had screen-detected COPD, 26.2% had self-reported COPD and 25.6% had newly documented COPD. During a median 11-year follow-up, 1185 acute myocardial infarction, 5778 other ischaemic heart disease, 1078 heart failure, 2390 pulmonary heart disease, 4989 ischaemic stroke and 1648 intracerebral haemorrhage cases occurred. Post-ECOPD risks of all outcomes were prominently elevated, with first-week hazard ratios (95% CI) of 8.60 (5.40-13.70), 6.68 (5.16-8.65), 10.98 (6.74-17.89), 24.76 (19.40-31.60), 3.11 (2.16-4.48) and 2.40 (1.27-4.54), respectively. The risks diminished thereafter but could persist for 6 years or longer. All three categories of patients with COPD faced increased risks of most outcomes, with patients with COPD at baseline bearing higher post-ECOPD risks of other ischaemic heart disease and pulmonary heart disease. CONCLUSION: CVD risks increased considerably after ECOPD, with risks of cardiac diseases and ischaemic stroke increased for 6 years or longer. Patients with screen-detected COPD had a similar burden of ECOPD and subsequent CVD to patients with doctor-diagnosed COPD.