Rotational thromboelastometry (ROTEM) can only detect high-degree hyperfibrinolysis (HF), despite being frequently used in trauma patients. We investigated whether considering FIBTEM HF (the presence of maximal lysis (ML) > 15%) could increase ROTEM-based HF detection's sensitivity. This observational cohort study was performed at a level 1 trauma centre. Trauma patients with an Injury Severity Score (ISS) > 15 who underwent ROTEM in the emergency department between 2016 and 2017 were included. EXTEM HF was defined as ML > 15% in EXTEM. We compared mortality rates between EXTEM HF, FIBTEM HF, and non-HF patient groups. Overall, 402 patients were included, of whom 45% were men (mean age, 52.5 years; mean ISS, 27). The EXTEM HF (n = 37), FIBTEM HF (n = 132), and non-HF (n = 233) groups had mortality rates of 81.1%, 22.3%, and 10.3%, respectively. The twofold difference in mortality rates between the FIBTEM HF and non-HF groups remained statistically significant after Bonferroni correction (P = 0.01). On multivariable Cox regression analysis, FIBTEM HF was independently associated with in-hospital mortality (adjusted hazard ratio 2.15, 95% confidence interval 1.21-3.84, P = 0.009). Here, trauma patients with FIBTEM HF had significantly higher mortality rates than those without HF. FIBTEM be a valuable diagnostic method to improve HF detection's sensitivity in trauma patients.