A clear cut relationship between particulate matter air contamination and the mortality and morbidity due to respiratory disease has been observed in the last decades. However there is also a relationship between air pollution and cardiovascular diseases. In big cities, a big or small particle concentration increase of 10 micro/m(3) is associated with a significantly higher risk of ischemic heart disease and myocardial infarction, both when acute or chronic exposures are considered. The risk is higher for small particles. Similar risk increases are observed in patients with hypertension, stroke or severe arrhythmias. This association is independent of environmental distracters such as weather, temperature or humidity and of classical cardiovascular risk factors such as age, diabetes, dyslipidemia and obesity. Physicians should be aware of the problem and explain their patients the increased risk that they are facing due to air pollution.