We tested the hypothesis that Chinese patients have a coagulation profile that is less prothrombotic than that of Caucasian counterparts after the Fontan procedure by determining the type and prevalence of anticoagulant and procoagulant deficiencies in Chinese patients and comparing the findings to those previously reported in Caucasian series. The liver function and coagulation factors were assessed in 21 ethnic Chinese patients, aged 17.0 +/- 5.6 years, at 10.7 +/- 4.0 years after the Fontan procedure. The results were compared to those of 21 age-matched Chinese controls with minor congenital heart disease. The prevalence of coagulation factor deficiencies in our patients was further compared to that reported in Caucasian patients. When compared with controls, patients had significantly lower protein C (p = 0.014), factors II (p = 0.024), V (p < 0.001), VII (p < 0.001), IX (p = 0.036), and X (p < 0.001), and higher bilirubin (p = 0.001) levels. The prevalence of protein C deficiency was 9.5%, whereas those of factor II, V, VII, IX, and X deficiencies were 0, 66.7, 9.5, 0, and 57.1%, respectively. When compared with Caucasian data, our data showed a significantly lower prevalence of protein C, total protein S, antithorombin III, factor II, and factor VII deficiencies. Furthermore, the previously reported increase in factor VIII levels was not found. In contrast, the prevalence of factor X deficiency was higher in our patients. This study provides the first evidence of ethnic differences in coagulation factor abnormalities after the Fontan procedure. The imbalance between procoagulant and anticoagulant pathways in Chinese patients favors a bleeding, rather than a thrombotic, tendency.