Although there are a number of studies on the coexistence of heart disease and COPD among patients acutely admitted to hospital, this relationship has not been accurately described in the general population. Especially data on the prevalence of both reduced lung function and impaired left ventricular ejection fraction (LVEF) are sparse. We used data from the 4th examination of The Copenhagen City Heart Study, which comprises 5,890 individuals with data on pulmonary and cardiac symptoms, risk factors for cardiovascular diseases, pulmonary function tests, ECG and relevant medical history. Among the participants a randomly selected subgroup of 3,469 individuals underwent both spirometry and echocardiography. The participants were classified according to COPD stage using the international GOLD staging according to FEV(1) in % of predicted. The prevalence of COPD was 5.7% for mild COPD (GOLD stage 1), 9.4% for moderate COPD (GOLD stage 2) and 2.5% for severe and very severe COPD (GOLD stages 3+4). Individuals with COPD were older and had a higher prevalence of cardiovascular risk factors and a higher prevalence of cardiovascular diseases. Among the echocardiographical findings, only the presence of left ventricular hyperthrophy was significantly more frequent among individuals with COPD (17.7%) than among participants without COPD (12.1%.), yet this relationship was no longer significant after statistical adjustment for age and gender. In the general population, subjects with COPD have a higher prevalence of cardiovascular diseases and an unfavourable cardiovascular risk profile compared with individuals without COPD, but this was mainly related to higher age among the participants with COPD.