Cytidine 5'-diphosphocholine (CDP-choline) has several physiological and pharmacological effects on various bodily functions, including hemostasis. This study determined the impact of CDP-choline on hemostasis in a trauma-hemorrhage (T-H) model in rats or under in vitro conditions or after chronic treatment via thromboelastography. Trauma-hemorrhage resuscitation was induced, and either saline (1 mL/kg) or CDP-choline (50 mg/kg) was injected intravenously just prior to resuscitation in the T-H group and at the same time point in the sham-control group. The effects of CDP-choline on thromboelastogram parameters, coagulation markers, and platelet aggregation were investigated under in vitro conditions (1.5 mM, 30- or 3-min incubation in blood or plasma) and after chronic use (50 mg/kg, i.p., 10 days). Acute CDP-choline treatment was shown to decrease the initial and maximum clot formation time, accelerate clotting rapidity, reduce the lysis percentage, and increase the coagulation index in the T-H resuscitation group, whereas the same treatment in the sham-control rats did not alter any of the thromboelastogram parameters. However, the incubation of whole blood with CDP-choline prolonged the initial and maximum clot formation time, and CDP-choline treatment significantly decreased the slopes of the disaggregation and aggregation curves when platelets were stimulated with ADP and collagen, respectively. Interestingly, the chronic use of this drug did not influence any of these hemostatic parameters. These data implicate that acute but not chronic CDP-choline administration may differentially alter the hemostatic parameters under diverse conditions. The drug may produce a hypercoagulable state in activated situations but cause opposite effects under normal in vitro conditions.