Purpose: To validate the value of Duplex Color Doppler Ultrasonography (DDU) for the incidence and location of postoperative deep vein thrombosis (DVT) that developed after hip surgery Materials and Methods: 260 consecutive patients who did not undergo any preventive treatment for DVT and underwent hip surgery (osteosynthesis for femoral neck and intertrochanteric fracture, acetabular fracture, and hip joint arthroplasty) from July, 2003 to May, 2005 were evaluated for the incidence of DVT. DDU was carried out on 7th postoperative day in all cases. Results: DVT was detected in 16 cases (6.2%) with 7 being in the femoral vein and 3 in the calf vein. Only two cases showed clinical symptoms such as pain and edema but no pulmonary embolism developed. Conclusion: The incidence of DVT obtained from DDU after hip surgery was 6.2 %, and no serious complications developed due to the early diagnosis. DDU is valuable as a screening test for postoperative DVT as well as for the prevention of serious complications such as pulmonary embolism.