Intravascular ultrasound (IVUS) is a modern method of visualizing the coronary arteries from the lumenal surface of the vessel [1]. The cross-sections of the intracoronary images make possible the measuring of the coronary artery size and assessing the structure of the vessel [2], which is extremely important in the context of cardiovascular diseases.The uniqueness of ultrasound is based on the fact that diferent layers of the coronary artery wall re"ect ultrasound waves diferently, anatomically preconditioned. Therefore, understanding the anatomical aspect of the vessel structure is the key to interpreting the intracoronary images. Even though IVUS is widely used in the leading clinics [3], for the majority, it is a less accessible procedure [4]. Unfortunately, IVUS remains an innovative procedure for much medical sta! and requires further explanation of coronary vessel morphology. The coronary artery size is variable and impacts the coronary stent implantation and optimization of the results of coronary revascularization [5, 6]. To our knowledge, there is no data on the size of coronary arteries ostia among the Ukrainian population using IVUS