Introduction: We are presenting the case of a young patient, admitted to our hospital after a cardio-respiratory arrest due to ventricular fibrillation, with successful resuscitation, with the suspicion of antero-lateral ST-segment elevation acute myocardial infarction (STEMI). This case report emphasises the fact that in medicine things are not always what they seem to be, as the result of the coronary angiography has shown. Methods: A 27 year old patient, while at work, develops a cardio-respiratory arrest due to ventricular fibrillation and is brought to our hospital with the suspicion of antero-lateral ST-segment elevation acute myocardial infarction (STEMI). On admission, the patient had orotracheal intubation and mechanical ventilation, the electrocardiogram showed ST-segment elevation in the antero-lateral teritory, high CK-MB (107 U/L). However, the ecocardiography indicated the absence of wall motion abnormalities. We must also point out a low kalium level (2.9 mEq/L). In this context, we decided to perform a coronary angiography Results: The coronary and aorta angiography showed an anomalous aortic origin of the left coronary artery (left main emerging from the right sinus, with separate origin from the right coronary artery). Also, the suspicion of an interarterial course between the aorta and the pulmonary artery was raised. This suspicion was later confirmed by the coronary computed tomography angiography. During the following days, the evolution was favourable, with detubation and correction of the metabolic disturbances. Conclusions: Anomalous aortic origin of coronary arteries is a rare congenital defect, which carries a high risk of sudden death and ischemical complication. The risk is particularly high when it is associated with an interarterial course between the great arteries.