Although the role of environmental factors in the development of acute myocardial infarction (AMI) has been clearly established, the role of genetic factors is still undefined. The aim of this study was to investigate the association between various gene polymorphisms in the haemostatic system and the risk of myocardial infarction in a very genetic restricted area population of Sardinian young adults with AMI. The study case-control involved 71 patients who had survived a first MI at a mean age of 47,2 years and 150 healthy subjects. No differences in the allele or genotype frequencies were seen between the study groups for the fibrinogen, prothrombin, factor V, factor VII, vWF, TM, PAI-1, TPO gene, and PLA and HPA-2 genes polymorphisms. Indeed differences statistically significant were detected for A5709G in the TPO gene (P= 0,041), and I/D dimorphism in the eNOS gene (P= 0,016). We therefore conclude that among all the investigated polymorphisms only the 5709G and eNOS4a alleles seem to confer protection against MI in the young age of Sardinian people.