A 59-year-old male patient affected by pleural mesothelioma presented with chest pain and localized ST elevation in the electrocardiogram. Urgent coronary angiography excluded an acute coronary occlusion, whereas high-resolution computed tomography of the chest revealed tumor infiltration and associated acute inflammation of the pericardial sac. This case illustrates how initial clinical evaluation during emergency conditions could be misled by the time-effectiveness imperative in the primary percutaneous coronary intervention era. In conclusion, early valorization of clinical signs and noninvasive diagnostic elements may add accuracy in directing the postadmission patient course.