Background: Deep Vein Thrombosis remains serious and common complication after orthopedic surgeries. The Autar DVT risk assessment scale is used for nursing assessment of all DVT patients. It has a simple scoring system to provide a patient risk category based on Virchow's triad of risk factors. Aim: To assess the risk factors of deep vein thrombosis among the patient undergoing orthopedic surgery Research design: A descriptive exploratory research design was utilized to conduct this study. Subjects: 122 adult patients undergoing orthopedic surgery. Setting: This study was conducted in orthopedic department and outpatient clinic at Al Azhar Assuit University Hospital. Tools: Tool (I) Patient assessment sheet and Tool (II) Autar Scale. Results: According to the Autar DVT Risk Assessment Scale, quarter of the studied patient were in the “moderate risk" category in the preoperative period (31.1%) and more than a quarter were in the “low risk"(45.1%) and less than one fifth were in the “high risk" (14.8%) and (9.0%) in the “no risk" category in the preoperative period. Conclusion: Based on the results of the present study ,can be concluded that; the orthopedic surgery patients understudy had moderate risk of DVT formation and the great risk factors of developing postoperative DVT after orthopedic surgery were aging, immobility and obesity. Recommendations: Nurses should use a standardized scale to identify the risk factors for DVT in patients undergoing surgeries such as (Autar Scale).