Increased white blood cell count has been reported associated with increase risk of coronary heart disease. We studied the relationship of white blood cell count to the 5 year incidence of coronary heart disease mortality in 152 men, without myocardial infarction or infection in the 6 months prior to the study. The coronary heart disease was determined by coronary arteriography study in all patients. None was treated by revascularization procedures (surgical or percutaneous transluminal coronary angioplasty). The severity of coronary heart disease was assessed by Gensini's Score and number of main coronary arteries with significant stenosis. The white blood cell count showed a positive correlation with Gensini's Score (r = 0.45, p < 0.01), and was significantly higher in the patients with three vessels disease (one vessel = 7084 +/- 1679 leukocytes/mm3; two vessels = 7768 +/- 1860 leukocytes/mm3; three vessels = 8174 +/- 2016 leukocytes/mm3; p < 0.05). The patients who died differed significantly from the survivors as regards total leukocyte count (8309 +/- 2271 against 7548 +/- 1702 cells/mm3; p < 0.05). Multivariate analysis, using a stepwise logistic regression, identified the white blood cell count as the more strong independent predictive variable for Gensini's Score (r = 0.42, p < 0.001). We conclude that, in our experience, increased white blood cell count may contribute to the initiation and progression of the coronary heart disease, and was associated with a shorter subsequent survival time.