Current guidelines for the management of patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) recommend the administration of dual antiplatelet therapy with aspirin and an ADP receptor blocker "as early as possible" before angiography (upstream), though this suggestion is not based on the results of randomized clinical trials designed to investigate pre-hospital rather than in-hospital drug administration. The present review analyzed randomized clinical trials, registries and observational studies that assessed clopidogrel, prasugrel and ticagrelor administration in STEMI patients undergoing primary PCI to evaluate if their upstream use may be justified in clinical practice. A significant difference favoring early clopidogrel administration has been demonstrated in observational studies. No evidence is available for prasugrel and ticagrelor; however, the initial delay of their antiplatelet effect in STEMI patients could support an upstream strategy to obtain complete platelet inhibition in the first hours after PCI and prevent major adverse events (e.g., stent thrombosis) despite an increased risk of major bleeding, particularly in case of urgent bypass surgery. Data from specifically designed randomized clinical trials are warranted to establish whether early administration of prasugrel and ticagrelor may favor reperfusion and improve clinical outcome with an acceptable risk-benefit ratio.