A prospective study of 62 knee arthroplasty limbs from 60 patients was undertaken to evaluate the effectiveness of compression ultrasound when compared to venography in detecting deep venous thrombosis (DVT). The study was conducted in a double-blind nature. Compression ultrasound and venographic examinations were conducted on the same day within 5-8 days postoperatively. Compression ultrasound had a sensitivity of 85.7%, a specificity of 94.5%, and an accuracy of 93.5% when venography was considered as the gold standard or 100% correct. Positive and negative predictive values were 66.6% and 98.1%, respectively. Eight patients were diagnosed with acute DVT. Five patients presented with calf DVT, one patient had calf DVT extending into the popliteal space, and two patients developed thigh DVT. The authors conclude that compression ultrasound is an efficacious method to evaluate knee arthroplasty patients for deep vein thrombosis.