Angiotensinogen and its cleaved forms angiotensin I and angiotensin II are important regulators of blood pressure. The gene for angiotensinogen (AGT) carries two common polymorphisms, T207M and M268T (previously described as T174M and M235T). To investigate the role of haplotypes formed by these polymorphisms for angiotensinogen levels we examined blood pressure, coronary artery disease (CAD), myocardial infarction (MI), and AGT genotypes and haplotypes in 2,575 patients with angiographically documented CAD and 731 individuals in whom CAD had been ruled out by angiography. Three haplotypes, designated as Hap1 (T207, M268), Hap2 (T207, T268) and Hap3 (M207, T268), accounted for more than 99% of alleles. The AGT Hap2 haplotype was significantly associated with angiotensinogen levels; one additional Hap2 allele accounted for an approx. 8% increase in angiotensinogen. This association was stronger than that of either single polymorphism. AGT genotypes or haplotypes were not related to hypertension, CAD or MI. We conclude that a common haplotype of the angiotensinogen gene is linked to angiotensinogen levels but has no major impact on blood pressure, hypertension, or cardiovascular risk.