We studied 70 patients to determine the relationship between the treadmill exercise score (TES) and the extent of coronary heart disease (CHD). Seventy patients (50 males, 20 females, mean age 53±10 years), who underwent selective coronary arteriography as well as the exercise stress test (EST) carried out according to the Bruce protocol, were involved in the study. The TES was calculated with the formula proposed by Mark et al., and the patients were divided into low- moderate - and high-risk groups. Later, EST and arteriographic data were compared. The relationship between the TES and the extent of CHD was direct, with 69.6% of the TES - determined high-risk group showing of significant CHD; and moreover, 26% of this group had three-vessel disease, compared with 38% of the moderate-risk group and 4.7% of the low-risk group (p