Thromboelastography (TEG) has been part of the assessment of patients receiving massive transfusion (MT) at Haukeland university hospital (HUH) since 2007. However, the test has been used inconsistently, and in general, the value of the test in evaluation of patients with critical bleeding is still debated, although it has been suggested that the TEG-guided treatment decreases blood usage. This single-centre retrospective study examines the use of TEG and discusses its place as part of assessing MT patients. The study focuses on the amount of blood product transfused in TEG-tested and non-TEG tested patients and whether TEG assisted coagulation therapy has affected mortality compared to conventional coagulation tests (CCTs). The study is based on the data from the massive transfusion study (MTS) 2002-15. 241?MT patients were identified, and they were grouped into patients assessed with TEG and patients who did not get this evaluation. In a sub-analysis, the patients with the initially (first TEG-test) 30 best and 30 worst TEG curves were defined based on normal ranges for the parameters R-time, a-angle, Maximal Amplitude (MA) and lysis after 30?min (LY). Survival rate and blood product usage were compared between these groups and between TEG and non-TEG patients. 111 patients were tested with TEG and 130 were not. The patients with highly pathological TEG curves (worst) have significantly higher mortality than the 30 normal-TEG patients (best) after 24?h (p?