The authors investigated whether two objective allergy markers, peripheral blood eosinophilia and skin tests for common aeroallergens, were associated with cardiovascular death. Of 5,382 subjects in the Vlagtwedde-Vlaardingen Study (the Netherlands) with data on allergy markers in 1965-1972, 507 subjects died from cardiovascular disease during 30 years of follow-up. Subjects with eosinophilia had an increased risk of cardiovascular death (relative risk (RR) = 1.7; 95% confidence interval (CI): 1.4, 2.2), including ischemic heart disease death (RR = 1.6; 95% CI: 1.2, 2.2) and cerebrovascular death (RR = 2.3; 95% CI: 1.4, 3.8), independent of major risk factors. This association was limited to subjects with a percentage of the predicted forced expiratory volume in 1 second (FEV1 % predicted) of <100%. Positive skin tests were associated with a significantly reduced cardiovascular mortality in subjects with normal lung function and weight who did not smoke (RR = 0.15; 95% CI: 0.05, 0.46). Conversely, when subjects with positive skin tests had a body mass index of > or =25 kg/m2, had an FEV1 % predicted of <80%, or smoked, they had an increased risk for cardiovascular mortality. These results were not restricted to asthmatics. Our data suggest a possible link between eosinophilia and positive skin tests and cardiovascular mortality, especially in combination with other risk factors associated with its mortality.