Dual antiplatelet therapy (DAPT) represents the standard of care for patients undergoing percutaneous coronary intervention (PCI). Increasing evidence indicates that a "one-size-fits-all" approach with the use of a standard DAPT regimen for all patients undergoing PCI could lead to either suboptimal efficacy or prohibitively high bleeding in specific cohorts of patients. Moreover, the broad interindividual variabil-ity in response to P2Y12 inhibitors can impact outcomes and resource utilization. Among the strategies proposed to provide a more balanced trade-off between bleeding and ischemic events at a single pa-tient level, a guided selection of P2Y12 inhibitors, by using platelet function or genetic testing, has shown promising results. In this review, we provide a focused summary of the rationale and evidence on the use of platelet function and genetic testing-guided antiplatelet therapy, and we explore the implications for their use in the modern setting of patients undergoing PCI.(c) 2021 Elsevier Inc. All rights reserved.