Data have been accumulating that indicate that matrix metalloproteinase (MMP) gene polymorphisms contribute to inter-individual differences in susceptibility to and outcome of cardiovascular disease. This is currently best exemplified by the MMP3 gene 5A/6A polymorphism which has an effect on MMP3 expression and has been shown to be associated with coronary stenosis, myocardial infarction, coronary artery calcification, post-angioplasty coronary restenosis, carotid atherosclerosis, stroke, arterial stiffness, and blood pressure. Functional polymorphisms in the MMP1, MMP2, MMP7, MMP9, MMP12, and MMP13 genes have also been related to coronary artery disease, arterial stiffness, and/or abdominal aortic aneurysm. These genetic findings support the notion that MMPs play important roles in the pathogenesis of these conditions. There is also some evidence suggesting that MMP genotyping could aid in identifying patients who are likely to have unfavourable prognosis and/or adverse response to treatment.