Nonalcoholic fatty liver disease (NAFLD) is an important cause of liver failure. Whatever its cause, the liver failure is accompanied by multiple changes in the hemostatic system. The objective of the current report was to study several homeostasis parameters such as protein C, protein S, factor 7, factor 8 levels, platelet counts, prothrombin time and activated partial thromboplastin time, and plasminogen activator inhibitor in patients with fatty liver. A total of 28 consecutive patients with ultrasound proven NAFLD and 33 healthy volunteers were included in the study. Plasma prothrombin time and activated partial thromboplastin time were within normal ranges in both NAFLD and control groups. Plasma factor 7, factor 8, protein S, and protein C levels were decreased in NAFLD patients but the difference was not statistically significant, whereas plasminogen activator inhibitor 1 levels were significantly increased in patients with NAFLD compared to controls. In conclusion, in all types of liver disease, some alterations in hemostatic parameters are awaited. As fatty liver disease is very common in clinical practice, clinicians should be aware of this kind of alterations. Blood Coagul Fibrinolysis 21:325-327 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.