The authors present the case of a 52-year-old patient with the symptomatology of unstable angina pectoris where they diagnosed a major stenosis of the trunk of the left coronary artery as the only significant lesion in the coronary circulation. The patient was successfully treated by means of an intravascular ultrasound--guided coronary stent implanted into the trunk of the left coronary artery. The authors discuss the possibilities and trends of contemporary catheterization treatment of major coronary affections.