Intracardiac thrombosis (ICT) and pulmonary thromboembolism (PE) after cardiopulmonary bypass (CPB) are life-threatening events, but pathological mechanisms are not yet well defined. The aim of this review is to provide an update of case literature of a postbypass hypercoagulable state. Case commonalities among 48 ICT/PE events included congestive heart failure (50%), platelet transfusion (37.5%), CPB duration greater than 3 hours (37.5%), and aortic injury (27.1%). Preexisting thrombophilia was rarely reported, and 16.7% had low activated clotting time, ≤400 seconds during CPB. Mortality rate was very high (85.4%), despite attempted thrombectomy and supportive therapy. Thrombolytic therapy was infrequently used (5 of 48 times), but its efficacy is questionable due to common use of antifibrinolytic therapy (77.1% of cases). Acute ICT/PE events appear to rarely occur, but common features include prolonged CPB, depressed myocardial function, major vascular injury, and hemostatic interventions. Further efforts to elucidate pathomechanisms and optimize anticoagulation during CPB and hemostatic interventions after CPB are warranted.