Background: The role of the Fc gamma receptor IIa (Fc gamma RIIa), a receptor for C-reactive protein (CRP), the classical acute phase protein, in atherosclerosis is not yet clear. We sought to investigate the association of Fc gamma RIIa genotype with risk of coronary heart disease (CHD) in two large population-based samples. Methods: Fc gamma RIIa-R/H131 polymorphisms were determined in a population of 527 patients with a history of myocardial infarction and 527 age and gender matched controls drawn from a population-based MONICA-Augsburg survey. In the LURIC population, 2227 patients with angiographically proven CHD, defined as having at least one stenosis >= 50%, were compared with 1032 individuals with stenosis <50%. Results: In both populations genotype frequencies of the Fc gamma RIIa gene did not show a significant departure from the Hardy-Weinberg equilibrium. Fc gamma RIIa R(-131) -> H genotype was not independently associated with lower risk of CHD after multivariable adjustments, neither in the MONICA population (odds ratio (OR) 1.08; 95% confidence interval (CI) 0.81 to 1.44), nor in LURIC (OR 0.96; 95% CI 0.81 to 1.14). Conclusion: Our results do not confirm an independent relationship between Fc gamma RIIa genotypes and risk of CHD in these populations.