There is increasing evidence that ambient air pollution is associated with coronary heart disease morbidity and mortality. This research has focused on the general public and less so on possible sensitive subgroups even though these may have even greater susceptibility to adverse effects of ambient air pollution. With highly prevalent traditional as well as nontraditional risk factors, renal transplant recipients may potentially be a sensitive subgroup. The purpose of this study was to evaluate the possible effect of between long-term exposure to air pollution on the risk of CHD mortality among renal transplant recipients. This cohort study includes 32,239 adult, renal transplant recipients, transplanted between 1997-2002, identified through the US Renal Data System (USRDS) and living in the continental U.S.A. Monthly concentrations of O ₃, NO₂, SO₂, PM₁₀ and PM_2.5 were calculated from ambient monitoring data and interpolated to ZIP-code centroids according to the residence of the renal transplant subjects. Time dependent Cox Proportional Hazard models were used to estimate the effect of ambient air pollutants on risk of CHD mortality, while adjusting for potential confounders. For each increase of 10 ppb increase in O₃ the risk of fatal CHD increased by 52% (Relative Risk (RR)=1.52, 95% Confidence Interval (CI): 1.34-1.73) in the single pollutant model and by 54% (RR=1.54, 95% CI: 1.36-1.76) in the two-pollutant model adjusted for PM₁₀. The pollutant with the strongest association with fatal CHD was PM_2.5 adjusted for O₃ (RR=1.89, 95%CI, 1.22-2.91). A small and significant association was found for SO₂, but no association was found for either NO ₂ or PM₁₀. In both the age- and multivariable adjusted models, there was a significant association between risk of fatal CHD and O₃ for both males and females, with females exhibiting the strongest association with each 10 ppb increase (RR_males=1.43, 95%CI: 1.26-1.63 and RR _females=1.67, 95%CI: 1.39-2.00). Ambient levels of fine particulate matter and ozone are associated with risk of fatal CHD among renal transplant recipients. These findings could have potential implications for policies and regulations of air pollution. Additionally, these results may be relevant in developing individual CVD risk reduction strategies for renal transplant recipients to ultimately improve long-term survival.