Cardiovascular disease is a major global cause of mortality, and its fundamental underlying substrate is atherosclerosis. Young and old patients have different risk factor profiles, clinical presentations, angiographic findings and prognosis. We performed a retrospective case-control study in a cohort (cases) of premature coronary disease (<or=45 years, n=200) compared with consecutive (controls) older patients (>45 years, n=200). The proportion of premature coronary disease in our geographic area was 9%. The average age of the case group was 41 and 64 years in controls (p<0.001). The male sex, though majority in both groups, was significantly more prevalent in the young group (92.5%) than in the older group (76.0%, p<0.001). The presence of smoking habit, hyperlipidemia and family history was significantly higher in the case group as well, with smoking habit being the most prevalent risk factor. In contrast, hypertension and diabetes were more frequent in controls. The number of affected vessels in cases was significantly less than the control group (1.4+/-0.8 vs. 1.7+/-0.9; p=0.013). Premature coronary disease affects predominantly the male sex and shows high prevalence of cardiovascular risk factors, mainly tobacco, hyperlipidemia, and family history of ischemic heart disease. In addition, it is characterised by a less extensive coronary atherosclerosis, mainly with the higher presence of single-vessel disease in contrast to older patients, as well as lower initial mortality.