Radionuclide venographies were performed in 138 limbs of 58 patients and X-ray contrast venographies were performed in 23 patients of them. Positive radionuclide venography findings were area of decreased radioactivity flow corre-sponding to the region of thrombosis, abnormal collateral flows and radioactivity stasis below the lesion. The success rate of radionulide venography was 89% and the overall concordance between radionuclide venography and X-ray contrast venography was 91%. Radionuclide venography is simple and easy to perform and less invasive than X-ray contrast venography. These results indicate that radionuclide venography is the most ideal screening test for the detection of venous thrombosis in patient with signs & symptoms of deep vein thrombosis.