: In this article we provide a very interesting and challenging PCI of unrecognized anomalous left circumflex coronary artery (LCx) arising from right sinus of Valsalva (RSV) after aortic valve replacement (AVR).This case presentation focuses the attention on important criteria for recognition of abnormal LCx coronary artery, that is the most frequent congenital coronary variant. Failure to demonstrate the anomaly can lead to erroneous interpretation of coronary anatomy with fatal complication in case of aortic valve replacement, as a consequence of accidental ligation or compression of the anomalous vessel. This procedure, especially in the presence of a bioprosthesis aortic valve just implanted, constitutes a challenge for the interventional cardiologist and at the same time a question mark regarding the strategy, choice of guiding catheter, guide wire, and type of stent to use.