Fifty-three Hong Kong Chinese patients with fractures of the proximal femur have been studied after hip surgery using functional ascending phlebograms for evaluating deep vein thrombosis. There was an incidence of deep vein thrombosis of 53.1 per cent in the fractured limbs and 14.3 per cent in the uninjured limbs. The majority of thrombi (84.6 per cent) were located in the calf. No clinical or fatal pulmonary embolism was observed.