Thirteen of 32 patients with coronary heart disease who also exhibited symptoms and signs of severe time urgency and hostility (the two overt components of type A behavior [TAB]) were found to exhibit multiple episodes of silent myocardial ischemia over a 48-hour period of Holter monitoring as indicated by electrocardiogram ST depressions. Ten of these 13 patients were given 14 months of TAB counseling in an attempt to diminish the intensity of their time urgency and hostility. The remaining three patients served as controls. After counseling, the intensity of the time urgency and hostility of the 10 counseled patients diminished 53% and 59%, respectively, as measured by the videotaped clinical examination. The time urgency and hostility of the three uncounseled control patients did not significantly change. The mean frequency of ischemic episodes in the 10 patients who received TAB counseling significantly declined from an initial 6.6 to 3.1 ischemic episodes per 24 hours. However, the mean frequency of ischemic episodes did not significantly decline in 2 of the 3 uncounseled patients. The third uncounseled patient developed a conduction defect in the 14-month interlude, making an analysis of his repeat 48-hour electrocardiogram for episodes of ST depression impossible.