: In thrombocytopenia, differences in haemostatic capacity may explain discrepancies in bleeding risk between patients with cancer and patients with liver cirrhosis. The objective was to compare the haemostatic capacity in different thrombocytopenic patient populations. We evaluated platelet aggregation using impedance aggregometry (Multiplate Analyzer), von Willebrand factor antigen (VWF:Ag), VWF:ristocetin-cofactor activity (VWF:RCo), activated partial thromboplastin time (aPTT), coagulation factor VIII, fibrinogen, and thrombin generation in adult hospitalized patients with platelet count less than 80 × 10/l. Patients either had liver cirrhosis (n = 28), or cancer (n = 169; n = 49 had haematological cancer) with no difference among patients with liver cirrhosis and cancer. Median platelet count was 48 × 10/l [interquartile range (IQR) 32-63 × 10/l]. Median platelet aggregation was higher in patients with cirrhosis than cancer, 416 AU × min (IQR 257-676) versus 145 AU × min (IQR 50-326) for collagen-induced platelet aggregation, P < 0.001. There was no difference in activated partial thromboplastin time (aPTT), coagulation factor VIII, or thrombin generation between the patient groups. Fibrinogen activity was higher in patients with cancer compared with patients with cirrhosis [12.5 μmol/L (IQR 9.9-16.5) versus 7.2 μmol/l (IQR 5.6-10.2)], P < 0.003. Patients with liver cirrhosis had a more preserved primary haemostasis compared with patients with cancer.