The authors evaluate the long-term fate of 1,254 conservatively treated patients suffering from ischaemic heart disease (IHD), in dependence on the results of submaximal ECG exercise test and coronary angiography. Survival rate was closely related to the heart rate achieved during exercise, the duration of exercise, presence or absence of subjective or ECG signs of coronary insufficiency during exercise, and on the degree of impairment of coronary circulation. Comparison of invasively and non-invasively obtained data confirms that submaximal ECG exercise test can contribute to a more accurate assessment of prognosis in patients with double- or triple-vessel coronary heart disease.