Background: Lower extremity venous thrombosis (LEVT) is the most frequent form of vascular involvement in Behcet's disease. Up to 17% of the mortality in Behcet's disease is reported to be associated with venous involvement such as pulmonary embolism or Budd-Chiari syndrome (BCS). Early recognition and appropriate management of vascular involvement in BD is essential to reduce associated morbidity and mortality. Homocysteine (hcy) may play a role in BD patient with venous affection. Objectives: To find out the role of homocysteine and venous Doppler ultrasonography in detection of venous insufficiency (VI) in BD patients. Subjects and Methods: A case control study, 50 patients with Behcet's diseaseand 50 age and sex matched healthy controls were included. Serum homocysteine (by ng/l) was determined by ELISA. Also measurement of VI by venous Doppler ultrasonography in lower limbs of Behcet's patients and controls. Results: In this study there was statistically significant difference between serum homocysteine level among BD patients and controls (p < 0.05). There was a significant difference between serum homocystiene levels in BD patients with venous versus non venous affections, p<0.05. There was a significal positive correlation between serum hcy levels and VI grades by Doppler US. Conclusions: Behcet's disease patients with hyperhomocysteinaemia and VI diagnosed by Power Doppler US should be considered as a strong indicator of pathological venous involvement.