The clinical use of intracoronary ultrasound imaging is growing, serving as a useful adjuvant to contrast angiography, and providing additional information to assist with catheter-based interventions. Despite the increasing use o f this technique, It remains an invasive procedure, the safety of which has not been definitively established. Data from multiple European centers performing intracoronary ultrasound (ICUS) examinations were collected under the auspices of the Subgroup on lntravascular Ultrasound of the Working Group on Echocardiography of the European Society of Cardiology. information was obtained about the number of examinations performed, complications related to iCUS imaging, and any adverse clinical consequences related to iCUS imaging. Twelve centers submitted information about their experience with ICUS. Eight (1.1%) compiications were reported (spasm, vessel dissection, or guide wire entrapment) in a total of 718 examinations. Ail complications occurred in patients with atherosclerotic coronary disease with a diagnosis of unstable or stable angina who underwent percutaneous transiuminal coronary angiopiasty. No permanent adverse clinical consequences due to iCUS imaging were reported. There was no difference in frequency of complications between centers, as assessed by chi-square analysis (P = 0.232). These data suggest that iCUS examinations can be performed safely with a very low rate of complications.