Platelet transfusion is an important modality for the prevention and treatment of bleeding. The majority of platelet transfusions are for bleeding prophylaxis in thrombocytopenic patients with appropriate transfusion threshold determined by the clinical scenario and anticipated bleeding risk. However, platelets are also instrumental for correcting coagulopathy and controlling active bleeding. Platelet transfusion is generally safe but subject to adverse events similar to the use of other blood products. Prevention, early recognition, and prompt treatment are critical. While some transfusion indications are well studied by randomized controlled trials, others rely on observational studies and expert opinion. Due to their short shelf-life, platelets are often in short supply and thus optimal transfusion strategies are crucial for maximizing benefit for the greatest number of patients.