IntroductionAnomalous aortic origin of the coronary arteries (AAOCA), a rare congenital malformation, is reported with a prevalence of less than 1% in angiographic series in average (1, 2). Among these, anomalous origin of the left main coronary artery (LMCA) from the right coronary cusp is particularly uncommon and is associated with variable clinical consequences depending on its course (1).Clinically, many cases are asymptomatic and considered benign. But some of the AAOCA variants like when the left coronary artery arises from the right sinus and courses between the aorta and pulmonary artery (inter-arterial course), are considered high risk. They are potentially associated with myocardial ischemia, angina, syncope, and sudden cardiac death (SCD), particularly in young athletes and active individuals (3, 4).Patients with anomalous LMCA may present with a wide spectrum of symptoms, ranging from exertional chest pain to acute coronary syndromes, or the anomaly may be discovered incidentally during imaging (1, 3). Multimodal imaging, particularly coronary angiography combined with computed tomography angiography (CTA), is often required to define the course of the anomalous vessel and to guide therapeutic decision-making.We present the case of a 56-year-old woman with unstable angina and ST-segment elevation who was found to have an anomalous origin of the LMCA from the right coronary cusp with a prepulmonic trajectory, in the setting of significant multivessel coronary artery disease.