1. One hundred patients with fractures of the upper end of the femur were investigated clinically and radiographically to ascertain the incidence and site of deep venous thrombosis during convalescence.

2. The technique of phlebography used has its own inherent dangers, but we believe that familiarity with the technique reduces the risk of complications.

3. The investigation revealed thrombi that were clinically unsuspected and indicates a need for further investigation of factors such as manipulation and retraction that may promote deep thrombosis.

4. The study has provided a control series for an investigation of the effect of prophylactic anticoagulants upon the incidence of deep venous thrombosis and pulmonary embolism after fractures about the hip.