Surgical coronary revascularization was considered standard of care for left main stem stenosis for decades; however, in recent years, this type of coronary artery disease is treated increasingly more by percutaneous coronary intervention (PCI). It remains controversial which procedure should be used for an individual patient and this topic was the subject of numerous studies with partly contradictory results. For suitable patients, some studies showed a non-inferiority of PCI over coronary artery bypass grafting (CABG), while others demonstrated a significant advantage for surgery. This CME article provides a comprehensive overview of the current national and international guidelines as well as major studies on left main stem stenosis and points out the potential advantages and disadvantages of each treatment modality. Furthermore, it shows how the establishment of an interdisciplinary coronary heart team can result in optimal patient-centered treatment.