The objective was to study the effects of ethanol on coagulation and fibrinolysis in whole blood. Blood samples from healthy volunteers were analyzed before and after in-vitro addition of ethanol in order to achieve ethanol concentrations of 0, 1, 2 and 4 per thousand, respectively (0, 22, 44 and 88 mmol/l). Coagulation and fibrinolysis were then assessed using rotational thromboelastometry. We found that increasing ethanol levels increasingly impaired coagulation as evaluated with rotational thromboelastometry, with a maximum prolongation of the clot formation time of 118% at an ethanol level of 4 per thousand (P < 0.000001). We also found a very strong impairment of fibrinolysis already at an ethanol level of 1 per thousand. This is the first study assessing the effects of ethanol on coagulation and fibrinolysis in a whole blood model. The impairment of coagulation is similar in nature to the impairment found in patients suffering from hypothermia. The impairment is at a level that may be of clinical importance (e.g. in patients suffering from trauma). The inhibition of fibrinolysis is obvious already at an ethanol level of 1 per thousand and it may be a contributing factor to the increased amount of coronary and cerebrovascular ischemic events after binge drinking.