Thrombelastography (TEG), a cell-based whole blood assay, may better reflect haemostatic competence than conventional coagulation assays and this was therefore evaluated including the clot forming parameters: R, angle and maximal amplitude in patients at ICU admission. This was a prospective, observational study of patients admitted to a general ICU at a tertiary care university hospital with an expected stay of more than 24 h. Blood samples for TEG and standard coagulation analysis were obtained at admission. The APACHE II and sequential organ failure assessment (SOFA) scores and 30-day mortality were recorded. At ICU admission, 106 patients (42%) showed hypocoagulability as evaluated by TEG and these patients had higher first day SOFA score (P <0.0001) and higher 30-days (42 vs. 13%, P <0.0001) mortality than patients presenting with a normal TEG. In 30-day survivors, admission platelet count (P = 0.05), angle (P <0.001) and maximal amplitude (P = 0.001) were higher and R decreased (P = 0.0013) compared with nonsurvivors. Hypocoagulability at admission as evaluated by TEG was an independent risk factor for 30-day mortality [adjusted odds ratio (OR) 3.5; 95% confidence interval (CI) 1.7-7.1]. Hypocoagulability as evaluated by TEG was frequent at admission in general ICU patients and associated with a higher rate of ventilator treatment, higher rate of renal replacement therapy and a higher use of blood products. Hypocoagulability is an independent risk factor for 30-day mortality.