International guidelines for the management of patients with ST-elevation myocardial infarction (STEMI) recommend various performance measures to monitor the quality of STEMI systems of care. Door-to-balloon (D2B) time (arrival at hospital to percutaneous coronary intervention, PCI) and overall health care system delay (first medical contact to reperfusion) are acknowledged as valuable performance measures when treating patients with primary percutaneous coronary intervention (PPCI). However, there is confusion regarding the exact definition of these performance measures, and moreover system delay and PCI-related delay (the extra delay acceptable to perform PPCI instead of fibrinolysis) are often used synonymously, which add confusion when considering reperfusion strategy. The present paper calls for a consensus regarding the use and definition of objective performance measures when treating patients with STEMI, and exemplifies why it is insufficient just to focus on D2B time.