Background. Cancer is one of the most common acquired causes of venous thromboembolism. Aim. To evaluate haemostasis disorders in patients with non-metastatic gastric cancer. Patients and methods. We studied 11 patients with non-metastatic gastric cancer (9 males and 2 females, median age 54 years) and 20 healthy subjects (15 males and 5 females, median age 48 years) control. We measured prothrombin time, activated partial thromboplastin time, coagulation time, clot lysis time, fibrinogen, clotting factors (II, VII, VIII, IX, X), C protein, S protein, AT Ill, activated protein C resistance, prothrombin 1+2 fragment, tissue plasminogen activator, and D-Dimer in all subjects. Results. Fibrinogen plasma levels were significantly higher in patients with non-metastatic gastric cancer than in control group (505±24 mg/dl vs 336±30 mg/dl, p<0.001). We also found a significant increase in prothrombin 1+2 fragment plasma concentration compared with controls (3. 8±0. 6 nM vs O. 83±0. 09 nM, p<O. 001). Plasma D-dimer levels were 20-fold higher in patients with non-metastatic gastric cancer compared with controls (9.5±0.4 ng/dl vs 0.4±0.05 ng/dl, p<0.001). Also tissue plasminogen activator was significantly higher in gastric cancer patients than in controls (20.8±2.32 nglml vs 9.1±1.37 ng/ml, p<0.011. Finally clot lysis time was significantly accelerated in gastric cancer patients compared with control subjects (81±t37 min vs 233±74 min, p<0.01). Conclusions. Patients with non-metastatic gastric cancer are at risk for thrombotic events due to the combined increase in fibrinogen plasma levels and thrombin formation.