Abstract Background Anomalous origin of the left circumflex coronary artery (LCx) from the right sinus of Valsalva (RSV) is the most frequent among anomalous aortic origin of the coronary arteries (AAOCA). The estimated prevalence is low (about 0.4%) and in most cases asymptomatic. Angina, shortness of breath, myocardial infarction has been described in some patients, although diagnostic and therapeutic management is controversial, particularly in elderly patients. Case presentation A 76-year-old female patient was admitted to our outpatient clinic for dyspnea and chest discomfort. In clinical history hypertension, dyslipidemia and diabetes were documented. Hemodynamic parameters, clinical examination and ECG were normal. Transthoracic echocardiography showed preserved global systolic function without abnormalities of regional kinesis and valvular diseases were excluded. Interestingly, in five chambers apical view, a binary structure in the atrioventricular groove above the mitral valve plane that seemed to cross the aorta perpendicularly (RAC sign) was detected. Furthermore, in parasternal short axis view, we visualized the origins of the left and right coronaries and a blood vessel behind the aortic root, as well as a small circle below the non-coronary aortic cusp in mitroaortic angle in the parasternal long axis view (Bleb sign) was identified. We hypothesized an anomalous origin of LCx from the RSV with a retroaortic anomalous course and this was confirmed by coronary computed tomography (coroCT), that excluded an intramural course and critical stenosis of coronary arteries. Finally, we decided to perform an exercise stress echocardiography which excluded inducible myocardial ischemia. Pharmacological therapy was optimized and clinical follow-up was unremarkable. Conclusions AAOCA may be incidentally diagnosed also in advanced age. Specific echocardiographic signs should suggest more advanced imaging techniques to confirm the diagnostic suspect. Non-invasive multimodality imaging is crucial, in order to exclude inducible myocardial ischemia and to avoid more invasive and harmful diagnostic tests.