Aortic stiffness predicts cardiovascular mortality and may be influenced by dietary fat composition. The hypothesis that plasma fat composition influences arterial stiffness and subsequent mortality was tested here in a prospective study. A total of 174 randomly sampled nondiabetic participants aged 45 to 74 years were recruited from local populations, stratified by ethnicity and gender, and followed up for mortality. Aortic pulse wave velocity (PWV), blood pressure, and fatty acid composition of plasma lipids were measured at baseline. PWV was associated with increased cardiovascular mortality and inversely related to the proportions of docosahexaenoic (rho=-0.22; P=0.02) and arachidonic acids (rho=-0.25; P<0.001) in plasma lipids. Principal component analyses identified a cluster characterized by higher proportions of palmitate, palmitoleic and oleic acid and lower proportions of linoleic, dihomo-gamma linolenic, and arachidonic acids. This cluster was positively associated with PWV, central adiposity, smoking, and increased mortality (hazard ratio: 1.13; 95% CI: 1.01 to 1.27). A second cluster, with higher proportions of arachidonic, eicosapentaenoic, and docosahexaenoic and lower proportions of oleic, palmitic, and linoleic acid levels, was associated with lower PWV and systolic blood pressure but also decreased risk of mortality (hazard ratio: 0.57; 95% CI: 0.39 to 0.82), independent of PWV and blood pressure. These data suggest that plasma fatty acid profiles characterized by a higher proportion of long-chain polyunsaturated fatty acids are associated with decreased cardiovascular mortality, independent of the impact of aortic PWV. The results are consistent with an effect of dietary sources of n-3 long-chain polyunsaturates influencing arterial stiffness and mortality.