We investigated heart rate and heart-rate variability in 82 patients, 60 men and 22 women (M = 54 yr., SD = 9) with acute coronary heart disease and scores on Bortner's scale at hospital admission and discharge. 48 patients were classified by their scores on Bortner's scale as Type A and 34 as Type B. Patients with acute coronary heart disease classified as Type A had a significantly lower mean heart rate than patients with acute coronary heart disease classified as Type B during the day at hospital admission and discharge and during the night at hospital discharge. Mean heart-rate variability was also significantly higher in the patients with acute coronary heart disease classified as Type A than in the patients with acute coronary heart disease classified as Type B during the day at hospital admission and discharge. The differences between two groups on the average heart rate and heart-rate variability were not significant during the night at hospital admission. In our study the patients with acute coronary heart disease classified by scores on Bortner's scale as Type A had higher vagal tone and more favorable sympathovagal balance than patients classified as Type B. This finding may have implications for the treatment of patients with acute coronary heart disease and may suggest some explanation about the protective effect of Type A behavior also.