Objective: The aim was to evaluate the predictive value of thromboelastometry for postoperative blood loss in adult cardiac surgery with cardiopulmonary bypass. Design: Retrospective cohort study and systematic review of the literature. Setting: A tertiary university hospital. Participants: 202 patients undergoing elective cardiac surgery. Interventions: Thromboelastometry was performed before cardiopulmonary bypass and 3 minutes after protamine administration. Measurements and Main Results: The cohort study showed that the preoperative and postoperative thromboelastometric positive predicting value was poor (0%-22%); however, the negative predicting value was high (89%-94%). The systematic review of the literature to evaluate the predictive value of thromboelastometry for major postoperative bleeding in cardiac surgery resulted in 1,311 articles, 11 of which were eligible (n = 1,765; PubMed and Embase, until June 2016). Two studies found a good predictive value, whereas the other 9 studies showed a poor predictability for major postoperative bleeding after cardiac surgery. The overall negative predicting value was high. Conclusions: Thromboelastometry does not predict which patients are at risk for major postoperative bleeding.