Abstract: Sodium Warfarin is one of the oral anti coagulant drugs that is used by some patients to avoid thromboemboli. For these patients one of the problems after the surgery is hemorrhage. These patients should be checked and evaluated before the surgery. The aim of this study, was to determine and compare the effect of interruption, adjusting and continuing warfarin on bleeding after tooth extraction. In an experimental study, we surveyed the effect of warfarin on bleeding for 17 patients with 81 extractions. On the basis of the received results from lab and the amount of Pro-Thrombin time (PT), The kind of problem and consulting with cardiovascular specialist on interruption, adjusting and continuing the use of drug were decided 0.37 extractions in group one (continuing the drug), 33 extractions in group 2 (drug adjustment) and 11 extractions in group 3 (discontinuing the use of the drug). All the patients underwent a bilateral symmetrical extraction of the teeth. The findings were analyzed by correlation coefficient, chi-square (χ²) and t-tests. The average amount of INR was 2.25 ± 0.55 in all 3 groups (SD = 0.55). The results showed average amount of PT in patients with no bleeding was 19.7±2.3, while in mild bleeding it was 19.3±4.7. In 3 groups no hemorrhage was observed after extraction in the first 30 min. During the first 24 h, only 8 of the extractions, who did not notice the post operative orders, showed signs of mild bleeding. The difference between group 1 and the other groups was not significant statistic cally (p>0.5). There was no hemorrhage in the 3 groups 48 h and 5 days after extraction. There was no significant relationship between hemorrhage and the type of systemic disease either clinically or statistically. It was concluded that continuing Warfarin if International Normalized Ratio (INR) is in the Normal Range (INR<4) poses no danger for the patient and if the patient is at risk of thrombo-emboli, continuing the drug is advised. In cases of INR>4 adjusting the drug should be taken into consideration. It is not advised to stop the medication if the consequences are irreparable.