The purpose of this angiographic study was to make a review of patients with coronary artery ectasia (CAE) and to compare the average coronary artery diameters of proximal, middle and distal segments of the following three groups of coronary arteries: Group E (ectatic segments in patients with CAE and ischaemic heart disease), Group E-n (presumably normal segments in the same group of patients) and Group N (normal coronary arteries of control patients). It was found that distal segments of all three coronary arteries and the middle segment of the circumflex artery in Group E-n were significantly narrower than the corresponding segments in Group N (p = 0.001 or less than 0.05 respectively), which suggested the arteriosclerotic origin of both, CAE and distal coronary artery involvement.