We studied 92 patients to determine the relationship between the QRS treadmill score (QTS) and extent of coronary artery disease. The results were compared to those of ST segment deviation in a < (+)QRS score > population. A cut off point of < 5 mm was used for mild to moderate risk patients whereas a QTS of < 3 was considered high risk for the patients. 43% of the patients had high risk QTS and 57% mild to moderate QTS. A highly significant correlation was observed between the extent of coronary artery disease and the high risk group of patients, whereas nonsignificant changes were observed in the control group (p < 0.001). Finally, the results indicate that in patients with a (+) QTS score (< 5 mm), coronary artery disease was significant and accordingly extensive during coronary angiography. On the other hand, a (+) QRS score proved to be superior to ST deviation in predicting critical coronary stenoses in the same population (F ratio; 41 vs 24).