The bronchiectasis and chronic obstructive pulmonary disease (COPD) overlap syndrome (BCOS) is increasingly recognized. BCOS is associated with poorer outcomes and increased mortality than in either disease alone. In the following article, the authors discuss why COPD and bronchiectasis might coexist, the radiological issues in diagnosing bronchiectasis in COPD, the understanding of prevalence and the factors that impact this, mortality and morbidity, microbiology associations, and the impact BCOS has on investigations and management.