The object of this study was to investigate the relationship between stress and the extent of coronary artery stenosis in 101 patients with coronary artery diseases. Global assessment of recent stress(GARS) scale and perceived stress response inventory were used to measure perception for stressors and stress responses. Biological variables such as the extent of coronary artery stenosis, the number of the affected lesions on coronary angiography, serum Low Density Lipoprotein(LDL)-cholesterol, High Density Lipoprotein(HDL)-cholesterol, and total cholesterol were measured in all the subjects. Scores of perceived stress related to changes in relationship and overall global scores on GARS scale had significantly positive correlation with the extent of coronary artery stenosis. On the other hand, scores of percieved stress related to changes in relationship and changes or no changes in routine had significantly positive correlation with the number of the lesions. Scores of perceived stress related to change or no change in routine also positively correlated with serum level of LDL-cholesterol and total cholesterol. In contrast, general somatic symptoms negatively correlated with the extent of coronary artery stenosis. Impulsive-aggressive behavior negatively correlated with the number of the lesions. However, impulsive-aggressive thinking positively correlated with LDL-cholesterol. The above results suggest that perception for stressors may negatively affect the extent of coronary artery stenosis, the number of the lesions, serum LDL-cholesterol and total cholesterol. However, some stress responses showed inconsistent effect on the above biological variables. Thus, strategies designed to modify perception for stressors and some stress responses are likely to help the patients minimize the extent of coronary artery stenosis and prevent the diseases.